Homework Help: Math: Statistics

Recent Homework Questions About Statistics

math statistics
For each probability and percentile problem, draw the picture. A random number generator picks a number from 1 to 9 in a uniform manner. 1) Give the distribution of X. X = 2) Enter an exact number as an integer, fraction, or decimal. f(x) = where <=x=> 3) Enter an exact ...
Sunday, July 15, 2012 at 1:50pm

statistics
if the mean is 250mg and the standard deviation is 75mg and 2% goes either right or left, what formula do i use to come out with a normal curve?
Sunday, July 15, 2012 at 12:18pm

statistics
The probability that a house is burglarized in the city is 5%. If 50 houses are randomly selected, what is the probability that none will be burglarized?
Saturday, July 14, 2012 at 9:15pm

Statistics
A local fire station receives an average of 0.5 rescue calls per day. Find the probability that on a randomly selected day, the fire station will receive fewer than two calls.
Friday, July 13, 2012 at 8:57pm

statistic
1.The state highway patrol stops every 5th car on highway 210 to check drivers' licenses and registrations. Which sampling technique are they using? systematic sampling -chose this one convenience sampling cluster sampling simple random sampling stratified sampling 2.You ...
Friday, July 13, 2012 at 6:56am

statistics
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Friday, July 13, 2012 at 12:55am

Statistics
A reseacher would like to determine whether a change in lighting to full spectrum light bulbs increases productivity on an assembly line. A sample of n= 36 participants is obtained, and the light bulbs over the line are replaced. under general/historical operating procedures, ...
Thursday, July 12, 2012 at 10:10pm

Statistics
Problem 1 Use the Old Faithful data labelled Duration as a sample for problem 1. a. Determine the proportion of instances that the duration was less than 240 seconds. Also express the proportion as a percent. (hint: proportion is number of successes divided by total number. b...
Thursday, July 12, 2012 at 7:04am

Statistics
An instructor for a college biology lab has each of her 12 students (you are one of those 12 students) take their own SRS of 25 plants from an experimental field. She lets you know that the heights (measured in cm) of the plants in the field follow a N(50,4) distribution. a. ...
Wednesday, July 11, 2012 at 10:03pm

Statistics
1) A sample of 49 observations is taken from a normal population. The sample mean is 55 and the sample standard deviation is 10. Determine the 99% confidence interval for the population mean. 2) The Fox TV network is considering replacing one of its primetime crime ...
Wednesday, July 11, 2012 at 4:34pm

statistics
a random sample of 80 college students was selected to participate in a experiment. the mean of the sample is 317 points, the standard deviation of 37 there are 310 students that didn't complete the experiment 1. compute the appropriate test statistic? 2. what is the ...
Wednesday, July 11, 2012 at 2:40pm

Statistics and Probability
Drawing from a set of six blue beads and three gold beads, use ratios to state the likelihood of each color being drawn; conducts experiments to test predictions. Show your work and explain your answer.
Wednesday, July 11, 2012 at 1:59pm

Statistics
A comparison is made between two bus lines to determine if arrival times of their regular buses from Denver to Durango are off schedule by the same amount of time. For 51 randomly selected runs, bus line A was observed to be off schedule by an average time of 53 minutes, with ...
Wednesday, July 11, 2012 at 11:40am

statistics
The scores on a test for a very large class is normally distributed with mean 64 points and standard deviation 6 points. The department decides to award A to the highest 5% scores. What is the minimum score to receive an A for the course? Round your answer (down) to nearest ...
Wednesday, July 11, 2012 at 7:15am

Statistics
Are you annoyed with spam e-mail? Suppose a random sample of 200 Kent State students was asked this question of which 80% said that they are annoyed. From the provided information we can find the following: sample percent = 80% (sample proportion = .80) standard deviation (S.D...
Monday, July 9, 2012 at 6:49pm

Statistics
I just need to know what formula I need to use to get started on this equation: A man that was shot out of a cannon and the mean is 140 feet, stand. dev. is 10, landing net is 28 feet long. To maximize the peron's probability of landing on the net, how far away from the ...
Monday, July 9, 2012 at 4:13pm

statistics
A 95 confidence interval for the proportion of men that have ever dozed off while driving is 007 to 0.14. For women, a 95% confidence intervAL for the proportion that have dozed off while driving is 0.19 to 0.25. Assume both intervals were computed using larg random samples ...
Monday, July 9, 2012 at 3:21pm

statistics
A sample of 200 students in a English class were asked- How long did you sleep last night? sample mean: 6.4 hours S.D. = 1.6 HOURS Standard Error = .11 hours sample size = 200 What type of data is used in this example? my answer: MEASUREMENT DATA What would happen to the size ...
Monday, July 9, 2012 at 3:16pm

Probability & Statistics
You want to rent an unfurnished one-bedroom apartment in Boston next year. The mean monthly rent for a random sample of 14 apartments advertised in the local newspaper is $1200. Assume that the standard deviation is $230. Find a 95% confidence interval for the mean monthly ...
Monday, July 9, 2012 at 10:12am

Statistics
What formula do I use to find: a man that was shot out of a cannon, mean is 140 feet, stand. dev is 10, landing net is 28 feet long. how far away should the edge of the net be? I just need a push!
Monday, July 9, 2012 at 12:50am

Statistics
What are the odds in favor of spinning a D on this spinner?
Sunday, July 8, 2012 at 11:05pm

Statistics
A class consists of 23 women and 83 men. If a student is randomly selected, what is the probability that the student is a woman?
Sunday, July 8, 2012 at 10:25pm

statistics
Using the categorical data for your team project, conduct a two sample, two-tailed hypothesis test for the proportion, with a 0.05 level of significance. Find and interpret each step. H0: H1: Test statistic = Critical value = p-value = Reject the null hypothesis or do not ...
Sunday, July 8, 2012 at 1:19pm

statistics
Using the numerical data for your team project, conduct a two sample, two-tailed hypothesis test for the mean, with a 0.05 level of significance. Find and interpret each step. H0: H1: Test statistic = Critical value = p-value = Reject the null hypothesis or do not reject the ...
Sunday, July 8, 2012 at 1:17pm

statistics
H0: ƒÊX = ƒÊY The mean (average) gas price in city X equals the mean (average) gas price in city Y during January 2012. H1: ƒÊX ‚ ƒÊY The mean (average) gas price in city X does not equal the mean (average) gas price in ...
Sunday, July 8, 2012 at 1:14pm

Statistics
Using the numerical data for your team project, conduct a two sample, two-tailed hypothesis test for the mean, with a 0.05 level of significance. Find and interpret each step. H0: H1: Test statistic = Critical value = p-value = Reject the null hypothesis or do not reject the ...
Sunday, July 8, 2012 at 1:12pm

Statistics
Suppose that out of 15,351 convicts who escaped from U.S. prisons, only 7667 were recaptured. Let p represent the proportion of all escaped convicts who will eventually be recaptured. Find a point estimate for p. Round your answer to four decimal places.
Sunday, July 8, 2012 at 11:07am

Statistics
Total plasma volume is important in determining the required plasma component in blood replacement theory for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that sample of 61 male firefighters are ...
Saturday, July 7, 2012 at 4:21pm

Statistics
What price do farmers get for their watermelon crops? In the third week of July, a random sample of 51 farming regions gave a sample mean of = $7.08 per 100 pounds of watermelon. Assume that is known to be $1.80 per 100 pounds. Find a 99% confidence interval for the population...
Saturday, July 7, 2012 at 3:55pm

Statistics
True or false? If the original x distribution has a relatively small standard deviation, the confidence interval for will be relatively short. Answer True False
Saturday, July 7, 2012 at 3:54pm

Statistics
True or False? As the degrees of freedom increase, the Student's t distribution becomes more like the standard normal distribution. Answer True False
Saturday, July 7, 2012 at 3:53pm

Statistics
In the third week of July, a random sample of 61 farming regions gave a sample mean of = $6.88 per 100 pounds of watermelon. Assume that is known to be $1.72 per 100 pounds. A farm brings 30 tons of watermelon to market. Find a 98% confidence interval for the population mean ...
Saturday, July 7, 2012 at 3:53pm

Statistics
Answer the question Yes or No. Sam computed a 90% confidence interval for from a specific random sample of size n. He claims that at the 90% confident level, his confidence interval does not contain . Is this claim correct? Answer a. No b. Yes
Saturday, July 7, 2012 at 3:52pm

Statistics
What price do farmers get for their watermelon crops? In the third week of July, a random sample of 52 farming regions gave a sample mean of = $6.68 per 100 pounds of watermelon. Assume that is known to be $1.94 per 100 pounds. A farm brings 35 tons of watermelon to market. ...
Saturday, July 7, 2012 at 3:51pm

Statistics
Total plasma volume is important in determining the required plasma component in blood replacement theory for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that sample of some male firefighters ...
Saturday, July 7, 2012 at 3:35pm

statistics
mean cholesterol is 175mg/dl..standard deviation =20mg/dl assume approx normal distribution ..is varied. what percentage has a cholesterol level above 155mg/dl?
Saturday, July 7, 2012 at 12:55pm

STATISTICS
An April 15, 2002 report in Time Magazine stated that the average age for women to marry in the United States is now 24.9 years of age. If the standard deviation is assumed to be 4.9 years, find the probability that a random sample of 33 U.S. women would show a mean age at ...
Saturday, July 7, 2012 at 12:22pm

statistics
An April 15, 2002 report in Time Magazine stated that the average age for women to marry in the United States is now 24.9 years of age. If the standard deviation is assumed to be 4.9 years, find the probability that a random sample of 33 U.S. women would show a mean age at ...
Saturday, July 7, 2012 at 11:02am

statistics
First graders who misbehave in school may be more likely to be regular smokers as young adults according to a new study presented in the July 2004 issue of the American Journal of Epidemiology. After following a group of U.S. first graders for 15 years, it was found that among...
Saturday, July 7, 2012 at 10:59am

statistics
According to a website about salaries, the national average salary as of October 2003 for a human resources clerk was $29,932. We assume that the annual salaries for clerks are normally distributed with a standard deviation of $1,860. (Give your answers correct to two decimal ...
Saturday, July 7, 2012 at 10:03am

Statistics
(1) Gluten sensitivity, which is also known as wheat intolerance, affects approximately 15% of people in U.S. Let p be the proportion in a random sample of 800 individuals who have gluten sensitivity. Find the probability that the value of p is (a) Within 0.02 of the ...
Saturday, July 7, 2012 at 7:32am

statistics
A random sample of size 36 is taken from a population with mean 50 and standard deviation 5. Find P( < 51.5).
Friday, July 6, 2012 at 6:53pm

statistics
Steven collected data from 20 college students on their emotional responses to classical music. Students listened to two 30-second segments from “The Collection from the Best of Classical Music.” After listening to a segment, the students rated it on a scale from 1 ...
Friday, July 6, 2012 at 6:37pm

Statistics
Find the probability of at least one match. n = 62 How do I figure out r?
Friday, July 6, 2012 at 5:52pm

statistics
I have: E=2.4/64=8/64.64=0.125 95% confidence interval ranges from 28-0.25=27.75 to 28+0.25=28.25 27.75 scores
Friday, July 6, 2012 at 4:37am

statistics
the mean IQ of statistics teachers is greater than 110. write the existing state and alternative hypotheses.
Thursday, July 5, 2012 at 8:56pm

statistics
how can you reword these research hypotheses to null hypotheses: a. smoking during pregnancy increases the risk of a child being born prematurely. b. regular exercise in older adults decreases blood pressure levels.
Thursday, July 5, 2012 at 5:08pm

math statistics
create a null hypothesis on these research questions: a. what are the differences between emergency room shifts on medication errors? b. On a clinical trial of a new drug what will be the effects over a currently used drug?
Thursday, July 5, 2012 at 4:56pm

Math (Statistics)
(Find Normal Proportions) The lengths of Atlantic croaker fish are normally distributed with μ = 10 inches and σ = 2 inches. a) Draw the distribution of fish lengths above the axis, and label the mean (which I believe is μ=10). b)Gently shade an area on the ...
Wednesday, July 4, 2012 at 11:50pm

Statistics/Math
U.S. Interstate 64 runs between Portsmouth, VA, at I-264 on the eastern end to St. Louis, MO, at I-270 on the western end. While passing through six states and five more major cities, I-64 intersects nine more interstate highways. The number of miles in each state is as ...
Wednesday, July 4, 2012 at 7:09pm

Statistics
How would you interpret the findings of a correlation study that reported a linear correlation coefficient of +0.3?
Wednesday, July 4, 2012 at 7:07pm

Statistics
A game at the state fair has a "guesser" guess the month of your birth. You win a prize if he misses your month by more than 2 months (for ex: if you were born in April, and he guesses February, he wins; if he guessed January, you win). For simplicity, assume that ...
Tuesday, July 3, 2012 at 6:22am

statistics
9) A 95% confidence interval for the true mean cholesterol of adult males based on 25 randomly selected subjects extends from 175 mg/L to 250 mg/L. A proper interpretation of the confidence interval would be that: A) 95% of the population has a cholesterol level between 175 ...
Monday, July 2, 2012 at 7:48pm

statistics
The authors state that the heights of women in North America are normally distibuted with a mean of 65.0 and a standard deviation of 3.5 inches. I am 64.5 inches. Using the parameters above, what percent of women in North America are shorter than I am?
Monday, July 2, 2012 at 6:23pm

statistics
8) In the following statement, which is the margin of error? 200 Americans were asked which subject they think about most. 65% +/- 10% said they think of Statistics the most.
Monday, July 2, 2012 at 4:45pm

statistics
For the major airlines, 21% of all flights depart at least 15 minutes late with a standard deviation of 5%. Currently, 24% of all American Airlines flights depart at least 15 minutes late. If American wants to be in the top 10% of all major airlines with the FEWEST late ...
Friday, June 29, 2012 at 3:28pm

STATISTICS
WHAT IS THE MEANING OF X~N(42,5,103.71)
Friday, June 29, 2012 at 5:00am

statistics
Acrylic bone cement is commonly used in total joint replacement to secure the artificial joint. Data on the force (measured in Newtons, N) required to break a cement bond was determined under two different temperature conditions and in two different mediums appear in the ...
Thursday, June 28, 2012 at 9:11pm

statistics
Breast feeding sometimes results in a temporary loss of bone mass as calcium is depleted in the mother's body to provide for milk production. An investigation gave the following data on total body bone mineral content (g) for a sample of mothers both during breast feeding...
Thursday, June 28, 2012 at 9:08pm

statistics
A particular report included the following table classifying 711 fatal bicycle accidents according to time of day the accident occurred. Time of Day Number of Accidents Midnight to 3 a.m. 38 3 a.m. to 6 a.m. 29 6 a.m. to 9 a.m. 64 9 a.m. to Noon 78 Noon to 3 p.m. 98 3 p.m. to ...
Thursday, June 28, 2012 at 9:07pm

statistics
In a statistic class, 10 scores were randomly selected with the following results were obtained: 74, 73, 87, 57, 71, 68, 65, 77, 67, 66. What are the inner fences?
Thursday, June 28, 2012 at 5:52pm

Statistics
what drawback of the standard deviation is illustrated by example?
Thursday, June 28, 2012 at 5:23pm

statistics
The weight of a product is normally distributed with a mean of 4 ounces and a variance of .25 "sq ounces." The company wants to classify the unit as a scrap in a maximum of 1% of the units if the weight is below a desired value. Determine the desired weight such that...
Thursday, June 28, 2012 at 3:51pm

statistics
how large a sample size is needed for 2 sided 95% confidence interval to have a length of 2 weeks when mean is 3.6
Thursday, June 28, 2012 at 3:17pm

statistics
The diameter of small Nerf balls manufactured at a factory in China is expected to be approximately normally distributed with a mean of 5.2 inches and a standard deviation of .08 inch. Suppose a random sample of 20 balls is selected. Find the interval that contains 87% of the ...
Thursday, June 28, 2012 at 12:07am

statistics
Three cards are randomly chosen, without replacement, from a standard deck of 52. The random variable X represents the number of hearts cards chosen. Construct the probability distribution for X.
Wednesday, June 27, 2012 at 6:56pm

statistics
A firm has 30% of its service calls made by a contractor, and 15% of these calls result in customer complaints. The other 70% of the service calls are made by their own employees, and these calls have a 5% complaint rate. Use Bayes’ theorem to find the probability that a ...
Wednesday, June 27, 2012 at 2:37pm

statistics
In a statistic class, 10 scores were randomly selected with the following results were obtained: 74, 73, 87, 57, 71, 68, 65, 77, 67, 66. What are the inner fences? What is the coefficient of variation?
Wednesday, June 27, 2012 at 2:13pm

statistics
The first sample had 49 subjects and 7 had blue eyes. The second sample had 465 subjects and 244 of these had blue eyes. What is the value of the pooled estimate of the proportion used to test the hypothesis that the population proportions of blue eyes are equal?
Tuesday, June 26, 2012 at 10:01pm

Statistics
A study was conducted in order to estimate u, the mean number of weekly hours that U.S. adults use computers at home. Suppose a random sample of 81 U.S. adults give a mean weekly computer usage time of 8.5 hours and that from prior studies , the population standard deviation ...
Monday, June 25, 2012 at 9:13pm

Statistics
How large a sample of U.S. adults is needed in order to estimate U with a 95% confidence interval of length 1.2 hours?
Monday, June 25, 2012 at 9:11pm

statistics
a the gym i notice women tend to work out together more then men. males together at gym 5 alone 7 women alone 6 together 6 what statistical test should i use what is the Ha and Ho what is the appropriate analysis and should the Ho be rejected
Monday, June 25, 2012 at 12:26pm

Statistics
Test a claim p=0.5 with the significance level of 0.05 and n=49 calculate beta when the true probability porportion is 0.7.
Monday, June 25, 2012 at 11:32am

Statistics
I bemieve the t test is paired , want to make usre beofre I run the stats. A researcher wanted to answer the following question: What is the difference in students' computer anxiety based on whether or not they own computers? The researcher surveyed 92 undergraduate ...
Sunday, June 24, 2012 at 3:16pm

Statistics
According to a survey, 21% of residents in a country over age 25 had earned at least a bachelor's degree. You are performing a study and would like at least 10 people in the study to have earned a bachelor's degree. a)How many residents of the country do you plan t ...
Sunday, June 24, 2012 at 2:03pm

Statistics
Three cards are drawn with replacement from a standard deck. What is the probability that the first card will be a spade, the second card will be a black card, and the third card will be a queen? Write your answer as a fraction or a decimal number rounded to three decimal places.
Friday, June 22, 2012 at 7:02pm

business math and statistics
A simple interest calculation provides a useful estimate of what compound interest will be if(a) the dollar amount is small.(b) the dollar amount is large.(c) the term is long.(d) the term is short.
Friday, June 22, 2012 at 9:44am

statistics
for a population with mean of u=50 and a standard devation o=8,find the following raw scores corresponding to each of the following z scores. z score 2.50,-.50,-1.50,.25,-1.00,.75 find the raw score(x) of the above numbers
Thursday, June 21, 2012 at 10:58pm

Criminal Justice -rsearch and statistics
I have to write a description of an original research project at least 4 pages long. I have to formulate a theory based on any subject that is relevant to the criminal justice system. My theory should be a definitive statement . There are 3 sections; Theory Construction Data ...
Thursday, June 21, 2012 at 4:31pm

Statistics
The minimum or maximum value that one would expect the test statistic to yield if the null hypothesis is true is an example of which of the following
Thursday, June 21, 2012 at 4:15pm

statistics
IQ scores are normally distributed with a mean u = 100 and a standard deviation o =15. Based on distribution, determine % of IQ scores between 100 and 120 =
Thursday, June 21, 2012 at 12:47pm

Math
A sample of 64 statistics students at a small college had a mean mathematics ACT score of 28 with a standard deviation of 4. Estimate the mean mathematics ACT score for all statistics students at this college. Give the 95% confidence interval.
Thursday, June 21, 2012 at 3:15am

Statistics
From Normal Distribution Table (z) what is the corresponding value for 0.091.
Wednesday, June 20, 2012 at 6:49am

Statistics
Fo each pair of variables, is the association likely to be positive or negative, or no association and why Car size in square feet and cost of car($) Temperature outside in the winter and propane consumed to heat house Amt of soda pop consumed and GPA
Tuesday, June 19, 2012 at 5:47pm

statistics
for the population consisting of four abservations 1,3,5,7, find the dampling distribution of the sample mean for sample size n=2
Tuesday, June 19, 2012 at 4:53pm

statistics
the lenght of a species of fish is normally distributed with a mean of 24.3 inches and a standard deviation of 1.8 inches. What is the lenght that is exceeded by 30%of these fish
Tuesday, June 19, 2012 at 4:35pm

Statistics
An organization is studying whether women have caught up to men in starting pay after attending college. They randomly sampled 28 women, who earned an average of $38,293.78 out of college with a standard deviation of $5,170.22. Twenty-four men were also randomly sampled, and ...
Monday, June 18, 2012 at 10:55pm

Statistics
A company has two factories in which they manufacture engines. Once a month they randomly select 10 engines from each factory and test if there is a difference in performance in engines made in the two factories. This month the average output of the motors from Factory 1 is ...
Monday, June 18, 2012 at 10:55pm

Statistics
A 95% confidence interval for a population mean, ?, is given as (18.985, 21.015). This confidence interval is based on a simple random sample of 36 observations. Calculate the sample mean, x ?, and the sample standard deviation, s. Assume that all assumptions and conditions ...
Monday, June 18, 2012 at 10:54pm

statistics
1. A random sample of 100 computers showed a mean of 115 gigabytes used with a standard deviation of 20 gigabytes. What is the standard error of the mean?
Monday, June 18, 2012 at 4:51pm

Statistics
A researcher determines that 42.7% of all downtown office buildings have ventilation probles. Is this census data or sample data?
Monday, June 18, 2012 at 4:26pm

Business Statistics
If M = 45 and SD = 5, what percentage of scores falls between 39 and 51.2? I need to work the problem in excel.
Monday, June 18, 2012 at 3:45pm

statistics
11. A local health care company wants to estimate the mean weekly elder day care cost. A sample of 10 facilities shows a mean of $250 per week with a standard deviation of $25. What is the 90 percent confidence interval for the population mean?
Monday, June 18, 2012 at 3:02pm

statistics
39% of households have some sort of high speed internet service. 15 homes are selected at random. the probability that 5 homes will have high speed service is?
Sunday, June 17, 2012 at 8:33pm

statistics
A biologist reports a confidence interval of (3, 2, 3, 8) when estimating the mean height in (in centimeters) of a sample of seedlings. The estimated margin of error is __________ , The sample mean is ________.
Sunday, June 17, 2012 at 3:05pm

Statistics
A professor receives, on average, 8 emails from students on the day before an online quiz. If the distribution of the calls is Poisson, what is the chance that he received at least 6 and at most 10 emails on such a day?
Sunday, June 17, 2012 at 1:44pm

statistics
Facebook reports that the average number of Facebook friends worldwide is 175.5 with a standard deviation of 90.57. If you were to take a sample of 25 students, what is the probability that the mean number Facebook friends in the sample will be 190 friends or more?
Saturday, June 16, 2012 at 9:04pm

statistics
Considering that a researcher can test at the <p = .05 (95%), p = .01 (99%), or p = .001 (99.9%) level for statistical significance, how would you use these three levels in relationship to risk to patients in implementing the decisions of your research?
Saturday, June 16, 2012 at 12:09am

Statistics
among customers- 70% buy popcorn, 40% buy ice cream, and 25% by both. Suppose you pick one customer at random. Find the probability the customer buys popcorn or ice cream.
Friday, June 15, 2012 at 7:04pm

college statistics
assume the population of heights of female college students mean of 64.37 inches standard deviation of 6,26 in and random sample of 74 find p(x>65.25)B. find p(x>65.25)c. why is formulas required to solve a different than c.
Thursday, June 14, 2012 at 6:57pm

statistics
Suppose that 65% of all California State students own a motorcycle. A random sample of 100 CS students is surveyed and 61% indicate that they own a motorcycle. a. What is the value of the population percent given to you in the problem? b. What is the value of the sample ...
Thursday, June 14, 2012 at 6:28pm

statistics
Let x be the number of courses for which a randomly selected student at a certain university is registered. The probability distribution of x appears in the table shown below: x 1 2 3 4 5 6 7 p(x) .04 .05 .08 .26 .39 .16 .02 (a) What is P(x = 4)? P(x = 4) = (b) What is P(x 4...
Thursday, June 14, 2012 at 3:15pm

Statistics
An IRS auditor randomly selects 3 tax returns from 59 returns of which 11 contain errors. What is the probability that she selects none of those containing errors? Round to four decimal places.
Thursday, June 14, 2012 at 11:16am

probability & statistics
Q: if A and B are independent events, how many of the following statements must be true? 1. A' and B are independent 2. A and B' are independent 3. A' and B' are independent is choice 3 the only one that is true?
Wednesday, June 13, 2012 at 10:00pm

probability & statistics
How many distinguishable permutations of letters are possible in the word COLORADO? is it 8!/3!?
Wednesday, June 13, 2012 at 9:57pm

statistics
A purchasing agent wants to estimate the mean daily usage of rye flour. She takes a sample for 50 straight days and find that the sample mean is 180 lbs with a sample standard deviation of 38.5 lbs. a)State the 90% confidence interval for the mean.b) State the margin of error
Wednesday, June 13, 2012 at 8:38pm

statistics
A CBS/New York Times poll found that 350 out of 757 adults said they would travel to outer space in their lifetime, given the chance. Estimate the true proportion of adults who would like to travel to outer space with 95% confidence level.
Wednesday, June 13, 2012 at 6:51pm

statistics
In order to test a new production method, 36 employees were selected randomly to try the new method. The mean was 75.79 parts per hour with a standard deviation of 28.25 parts per hour. Calculate a 95% confidence interval for the true mean production rate for the new method.
Wednesday, June 13, 2012 at 12:46pm

statistics
The proportion of adults in the US with basic literary skills is 43%. If a hypothesis test is performed on this, how should you (in terms of the claim) interpret a decision that rejects the null hypothesis?
Wednesday, June 13, 2012 at 12:26pm

statistics
I visited a beautiful flower garden yesterday and counted exactly 90 flowers. Each flower was either red or yellow, and the flowers were not all the same color. My friend made the following observation: No matter which two flowers you might have picked, at least one was bound ...
Wednesday, June 13, 2012 at 11:56am

statistics
A group of 50 teachers and school administrators attended a convention. If any two persons are picked at random, at least one of the two would be a teacher. From this information, what percentage of the people at the convention were teachers? Could someone help me start this, ...
Wednesday, June 13, 2012 at 11:53am

statistics
A final exam in sociology has a mean of 72 and a standard deviation of 9.2. If 35 students are randomly selected, find the probability that the mean of their test scores will be greater than 76. Round to tenth of a percent
Wednesday, June 13, 2012 at 11:25am

statistics
Suppose a box has eight differently colored tennis balls in it. The colors are green, blue, red, purple, orange, black, and white. if I will randomly pick out three balls (without replacement), then what is the probability that the balls chosen will be green, yellow, and red (...
Tuesday, June 12, 2012 at 11:39pm

Statistics
How is the rejection region defined and how is that related to the z-score and the p value? When do you reject or fail to reject the null hypothesis? Why do you think statisticians are asked to complete hypothesis testing? Can you think of examples in courts, in medicine, or ...
Tuesday, June 12, 2012 at 8:57pm

Elementary Statistics
Given a level of confidence of 95% and a population standard deviation of 13, answer the following: (A) What other information is necessary to find the sample size (n)? (B) Find the Maximum Error of Estimate (E) if n = 82.
Tuesday, June 12, 2012 at 8:31pm

Statistics
A stoplight at the corner of Lincolnway and Duff Avenue is red 20% of the time. For someone who drives through this stoplight 10 times a week, what is the probability that they will stop at least three times?
Tuesday, June 12, 2012 at 5:00pm

statistics
. Facebook reports that the average number of Facebook friends worldwide is 175.5 with a standard deviation of 90.57. If you were to take a sample of 25 students, what is the probability that the mean number Facebook friends in the sample will be 190 friends or more?
Tuesday, June 12, 2012 at 8:35am

statistics
Suppose that a researcher is interested in estimating the mean systolic blood pressure, , of executives of major corporations. He plans to use the blood pressures of a random sample of executives of major corporations to estimate . Assuming that the standard deviation of the ...
Tuesday, June 12, 2012 at 12:01am

statistics
drug company promises to help people lose at least 3 pounds per week. 15 people use the drug. they lose an average of 2.8 lbs per week with a standard deviation of .5lbs. is this a left tail or right tail and why?
Monday, June 11, 2012 at 8:08pm

statistics
1- The ages of a population of 300 is normally distributed, with a mean of 45 and a standard deviation of 4. If you randomly selected a member of the population, what is the probablity that his or her age would be greater than 49?
Monday, June 11, 2012 at 9:05am

statistics
How many infants should you sample if you want a margin of error of 10 minutes for a 95% confidence interval about the mean amount of sleep they get per day if the population standard deviation is assumed to be 96 minutes?
Monday, June 11, 2012 at 8:17am

statistics
An average office worker uses 10000 sheets of paper each year. Assume that the population standard deviation is 3000 sheets per year. Is it unusual for the office worker to use over 15000 sheets each year? What % of workers use at least 8000 sheets per year? Find P30. ...
Monday, June 11, 2012 at 8:10am

Statistics for Behavioral Sciences
A disease affects 9% of individuals in a population and a sample of 100 people is selected from the population. What is the probability of finding the disease in 15 people?
Monday, June 11, 2012 at 1:04am

statistics
The weights of a group of adult males are normally distributed with a mean of 180lb and standard deviation of 8lb. Find the probability that a randomly chosen male from this group weighs more than 190lb.
Sunday, June 10, 2012 at 9:00pm

Statistics
In a survey of 633 males ages 18-64, 395 say they have gone to the dentist in the past year. Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. The 90% confidence interval for the ...
Sunday, June 10, 2012 at 7:19pm

Statistics
A researcher wishes to estimate, with 95% confidence, the proportion of adults who have high-speed internet access. Her estimate must be accurate within 4% of the true proportion. A) Find the minimum sample size needed, using a prior study that found that 54% of the ...
Sunday, June 10, 2012 at 7:19pm

college statistics
consider a population with a mena =51.6 and a sd=5.9 (A) calculate the z score for x= 50.5 from a sample of size 47. (b) could this z score be used in calculating probabilities using table 3 in appendix b in text book ahy or ahy not
Saturday, June 9, 2012 at 5:06pm

statistics
The annual precipitation amounts in a certain mountain range are normally distributed with a mean of 88 inches, and a standard deviation of 10 inches. What is the likelihood that the mean annual precipitation during 25 randomly picked years will be less than 90.8 inches?
Saturday, June 9, 2012 at 3:05pm

stats
USA snapshot presented a bar graph depicting business travelers’ impression of wait times in airport security lines over the past 12 months. Statistics were derived from Travel Industry Association of American Business Traveler Survey of 2034 respondents. Is this a ...
Friday, June 8, 2012 at 9:03pm

maths and statistics
A company manufactures a product. The total fixed costs are $75 and the variab cost per unity is $5. 1)find an expression for the total cost in terms of Q,the quantity produced
Friday, June 8, 2012 at 8:06pm

Psychological Statistics
Simply reporting measures of central tendency or measures of variability will not tell the whole story. Using the following information, what else does a psychologist need to know or think about when interpreting this information? A school psychologist decided to separate some...
Thursday, June 7, 2012 at 6:41am

Elementary Statistics
1) Construct a confidence interval of the population proportion at the given level of confidence. x=60,n=300, 99% confidence. The 99% confidence interval is (_,_) 2) A researcher wishes to estimate the proportion of adults who have high-speed internet access. What size sample ...
Wednesday, June 6, 2012 at 10:22pm

Statistics
It is known that the standard deviation for the number of minutes women spend applying makeup everyday is 17 minutes if you want to construct a 95% confidence interval for the mean amount of time women spend applying make up with a margin of error of no more than 5 mins. At ...
Wednesday, June 6, 2012 at 10:02am

statistics
In a random sample of 50 babies 4 to 7 month old the average number of hours they slept per day turned out to be 14.2 hours with a standard deviation of 1.6 hours find and interpret a 90% confidence interval for the mean number of hours slept by babies at this age
Wednesday, June 6, 2012 at 9:58am

statistics
A lottery offers one $900 prize, one $600 prize, three $400 prizes, and five $100 prizes. One thousand tickets are sold at $6 each. Find the expectation of a person buys five tickets.
Tuesday, June 5, 2012 at 7:48pm

Statistics
87,89,90,90,98,99,99,101,102,103,104 Find the interquartile range.
Tuesday, June 5, 2012 at 4:06pm

Statistics
87,89,90,90,98,99,99,101,102,103,104 Within how many standard deviations of the mean is the value 102?
Tuesday, June 5, 2012 at 4:06pm

Statistics
87,89,90,90,98,99,99,101,102,103,104 Find the 25th and 75th percentiles.
Tuesday, June 5, 2012 at 4:04pm

Statistics
98,99,99,103,101,102,104,89,87,90,90 Find the 25th and 75th percentiles
Tuesday, June 5, 2012 at 3:32pm

Statistics
98,99,99,103,101,102,104,89,87,90,90 Within how many standard deviations of the mean is the value 102?
Tuesday, June 5, 2012 at 3:30pm

Statistics
98,99,99,103,101,102,104,89,87,90,90 Find the interquartile range.
Tuesday, June 5, 2012 at 3:29pm

college statistics
find the normal approximation for the binomial probability that x=5 where n=14 and p=0.3 compare this to the value of p(x=5) found in table 2
Tuesday, June 5, 2012 at 2:18pm

statistics
Suppose X has a mound-shaped distribution with sigma=9. A random sample of size 36 has a sample mean 20. Is it appropriate to use a normal distribution to compute a confidence interval for the population mean u?
Tuesday, June 5, 2012 at 9:41am

Statistics (random variable)
A contractor is interested in the total cost of a project on which he intends to bid. He estimates that materials will cost rs 25,000 and that his labour will be rs900 per day. If he the project takes X days to complete,the total cost of the project (in rupees) will be given ...
Tuesday, June 5, 2012 at 3:00am

statistics
The actual weights of bag of pet food are normally distributed.The mean of the weights is 50.0 lb,with a standard deviation of 0.2 lb. C)In a group of 50 bags,how many would yu expect to be within 1.5 standard deviations of the mean?
Monday, June 4, 2012 at 8:13pm

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