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October 21, 2014

October 21, 2014

**Recent Homework Questions About Statistics**

Post a New Question | Current Questions

**statistics**

12. Suppose we are estimating p and we have no prior estimate of p. Find the required sample size for a confidence level of 90% and a margin of error of 0.02.
*Wednesday, May 8, 2013 at 3:43pm*

**statistics**

11. Suppose we are estimating m. What happens to the required sample size as the population standard deviation increases while the confidence level and desired margin of error remain constant? A) It increases. B) It decreases. C) It does not change.
*Wednesday, May 8, 2013 at 3:43pm*

**statistics**

10. Using the results of a Newsweek poll conducted in March of 2009, a 90% confidence interval on the proportion of adult Americans who have a favorable opinion of Barack Obama is given by (0.699, 0.741). If everything else is the same, but the confidence level increases, ...
*Wednesday, May 8, 2013 at 3:42pm*

**statistics**

Using the results of a Newsweek poll conducted in March of 2009, a 90% confidence interval on the proportion of adult Americans who have a favorable opinion of Barack Obama is given by (0.699, 0.741). What is the margin of error?
*Wednesday, May 8, 2013 at 3:40pm*

**statistics**

According to a Gallup Poll conducted in March of 2009, 38% of American adults polled believe that global warming will pose a serious threat to them or their way of life in their lifetime. Assuming a sample size of 1000, calculate a 95% confidence interval for estimating the ...
*Wednesday, May 8, 2013 at 3:40pm*

**statistics**

7. Determine whether it is appropriate to apply the Central Limit Theorem for Proportions: sample size 35, sample proportion 0.95. A) Yes B) No
*Wednesday, May 8, 2013 at 3:39pm*

**statistics**

6. Which distribution has the larger mean? i) t distribution, (df = 30) ii) standard normal distribution A) i) B) ii) C) They are the same.
*Wednesday, May 8, 2013 at 3:39pm*

**statistics**

5. What happens to the width of our confidence interval for m if we increase the sample size but keep the confidence level the same? A) It increases. B) It decreases. C) It stays the same. D) It depends on the sample mean and standard deviation.
*Wednesday, May 8, 2013 at 3:38pm*

**statistics**

4. The Pew Research Center reported that 57% of Americans favored the Wall Street bailout of 2008. A random sample of 300 people showed that 155 people favored the bailout. If appropriate, test whether the population proportion of Americans is different from 57%. Use level of...
*Wednesday, May 8, 2013 at 3:38pm*

**statistics**

The National Coalition on Healthcare suggests that the mean annual premium that a health insurer charges an employer for a health plan covering a family of four averaged $12700 in 2008. A sample of 30 families of four yield a mean annual premium paid by their employer to be $...
*Wednesday, May 8, 2013 at 3:37pm*

**statistics**

2. We would like to test whether the population mean is less than 40. Suppose that a hypothesis test is conducted to determine if the mean of the population has decreased or not. Describe what a Type II error would mean for this example. A) Reject H0 when the population mean ...
*Wednesday, May 8, 2013 at 3:37pm*

**statistics**

According to CreditReport, the mean credit score in Georgia for 2007 was 668. Suppose that a hypothesis test is conducted to determine whether the mean credit score in Georgia has decreased since that time. Describe what a Type I error would mean in the context of this problem...
*Wednesday, May 8, 2013 at 3:36pm*

**statistics**

students who learned English as well as another language simultaneously score worse on the SAT critical Reading exam than the general population of test takers? The mean score among all test takers on SAT Critical Reading exam is 501 A random sample of 100 test takers who ...
*Wednesday, May 8, 2013 at 12:12pm*

**statistics**

do students who learned English as well as another language simultaneously score worse on the SAT critical reading exam than the general population of test takers? the mean score di 501. A random sample of 100 test takers who learned English as another language simultaneously ...
*Wednesday, May 8, 2013 at 12:08pm*

**statistics**

plain type fonts such as times new roman are easier to rean than fancy fonts such as gigi. a group of 25 voulunteer subjects read the same text in both fonts. (this is a matched pairs design. One-sample procedures for proportions, like those for means, are used to analyze data...
*Wednesday, May 8, 2013 at 11:18am*

**statistics**

Merchandise inventory purchases for a firm for a three-month period are: January: 2,000 units @ $12 per unit; February: 1,800 @ $14 per unit; March 2,600 units @ 15 per unit. What is the mean unit cost of merchandise inventory?
*Wednesday, May 8, 2013 at 10:37am*

**Data Gathering and Inference**

When the production manager finds the average life of her bulb-lifetime data, it is an example of what phase of inferential statistics? A. Data organization. B. Data gathering. C. Data analysis. D. Probability-based inference.
*Wednesday, May 8, 2013 at 10:20am*

**Statistics**

You have a ten question multiple choice test in your next class and you did not study at all. Each question has four choices and only one correct answer. You are going to guess on each question. What is the probability that you score at least a 20% on the test.
*Tuesday, May 7, 2013 at 5:34pm*

**statistics**

Find the value of Z that is smaller than 90% of all values of Z.
*Tuesday, May 7, 2013 at 3:46pm*

**statistics**

Participants from the National Health and Nutrition Examination Survey, 2003–2004, had a mean BMI of 28.3 with a standard deviation of 6.0. Assuming BMI is normally distributed, what proportion of the participants had a BMI measure over 35?
*Tuesday, May 7, 2013 at 3:45pm*

**statistics**

According to the Census Bureau's 2002 American Community Survey, the average travel time to work of workers 16 years and over living in Boston, MA, who did not work at home, was 28.2 minutes with a standard deviation of 0.79 minutes. A sample of 35 commute times is taken. ...
*Tuesday, May 7, 2013 at 3:43pm*

**statistics**

A certain professional soccer team runs a 4-4-2 formation on the field. This means they play with 4 defenders, 4 midfielders, 2 forwards, and 1 goalkeeper on the field. If the team has 6 defenders, 5 midfielders, 3 forwards, and 2 goalkeepers, how many different groups of 11 ...
*Tuesday, May 7, 2013 at 3:40pm*

**statistics**

Assume that body temperatures of healthy adults are normally distributed with a mean of 98.2°F and a standard deviation of 0.62°F. Find the 90th percentile of the sample mean body temperatures for samples of size 16.
*Tuesday, May 7, 2013 at 3:12pm*

**Statistics**

If x is a binomial variable with p = .4 and n = 25, write the probability that you would be looking for after you have applied the continuity correction factor for the following conditions for x: 3) x = 5 4) x > 5 5) x ≤ 5
*Tuesday, May 7, 2013 at 12:14pm*

**Probability and Statistics**

There are 15 marbles in a jar.Five are red,four are blue, and six are yellow.If you draw two blue at random (without replacement), what is the probability that the second marble is blue?
*Monday, May 6, 2013 at 9:05pm*

**statistics**

The probablility that a person drinks at least five cups of coffee per day is .24, and the probability that a person has high blood pressure is .08. Assuming that these two events are independent, find the probability that a person selected at random drinks less than five cups...
*Monday, May 6, 2013 at 8:00pm*

**statistics**

A player pays a $1 to play a game. With probability 0.001 the player wins $900, with probability 0.005 the players wins $10. What is the players expected win per game?
*Monday, May 6, 2013 at 4:44pm*

**statistics**

A random number generator draws at random with replacement from the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. In 5000 draws, the chance that the digit 0 appears fewer than 495 times is closest to 25%,30%,35%,40%,45%,50%
*Monday, May 6, 2013 at 2:28pm*

**Statistics**

A true-false test consists of 20 questions, each of which has one correct answer: true, or false. One point is awarded for every correct answer, but one point is taken off for each wrong answer. Suppose a student answers every question by guessing at random, independently of ...
*Monday, May 6, 2013 at 7:15am*

**statistics**

A manufacturing company produces 10,000 plastic glasses per week. This company supplies plastic glasses to another company, which packages the glasses as part of picnic sets. The second company randomly samples 10 glasses from the supplier. If at least eight of the sampled ...
*Sunday, May 5, 2013 at 11:52pm*

**Math- Statistics **

Suppose 60% of adults have a college degree. If I take a random sample of 80 adults, what is the probability at least 50% of them have a college degree?
*Sunday, May 5, 2013 at 10:57pm*

**statistics **

A test has 1 true false question and 2 multiple choice questions(A B C D). Draw a tree diagram and determine the sample space for the possible ways to answer the test.
*Sunday, May 5, 2013 at 9:00pm*

**statistics**

The manufacturer of a new compact car claims the miles per gallon (mpg) for the gasoline consumption is mound-shaped and symmetric with a mean of 24.6 mpg and a standard deviation of 11.2 mpg. If 30 such cars are tested, what is the probability the average mpg achieved by ...
*Sunday, May 5, 2013 at 8:15pm*

**statistics**

No calculation required. what test would be used to predict what the tuition will be in 20 years if it has gone up the past five years?
*Sunday, May 5, 2013 at 7:35pm*

**Statistics 7**

A doctor wants to estimate the HDL cholesterol of all 20 to 29 year old females. How many subjects are needed to estimate the HDL cholesterol within 2 points with 99% confidence assuming s-17.8 based on earlier studies. Suppose the doctor would be content with 90 % confidence...
*Sunday, May 5, 2013 at 6:11pm*

**STATISTICS**

Determine the point estimate of the population mean and margin of error for the confidence interval. Lower bound is 15, upper bound is 27. A)The point estimate of the population mean is ________. B) The margin for error for the confidence interval is _______. HELP
*Sunday, May 5, 2013 at 5:26pm*

**Statistics**

A researcher wishes to estimate the proportion of adults who have high-spped internet access. What size sample should be obtained if she wishes the estimate to be within .02 with 90% if A) She uses a previous estimate of 0.48? B) She does not use any prior estimates? Please ...
*Sunday, May 5, 2013 at 5:22pm*

**Statistics**

Maureen is a cocktail hostess in a very exclusive private club. The IRS is auditing her tax return. Maureen claims that her average tip last year was $4.75. To support this claim, she sent the IRS a random sample of 52 credit card receipts showing her bar tips. When the IRS ...
*Sunday, May 5, 2013 at 4:51pm*

**Statistics**

A random sample of 10 independent observations from a normally distributed population yielded the following values 51, 53, 49, 43, 47, 46, 45, 30, 60, 52. a) Estimate the standard deviation of the sampling distribution of means for samples like this one. b) Using á = ....
*Sunday, May 5, 2013 at 2:25pm*

**statistics**

The attendance at the school play on Friday was 95% of the attendance on Saturday night. If 203 people attended on Saturday night, estimate how many attended on Friday night. a minute agoEdit Question
*Sunday, May 5, 2013 at 9:58am*

**life orientation**

1.Identify and describe 3environment health hazards that cause ill health,crises and or disasters within your community or any other community within south africa and globaLly.include evidence that is current of the identifted issues.use graphs,statistics,pictures. 2....
*Sunday, May 5, 2013 at 5:56am*

**statistics**

the percent defective for parts produced by a manufacturing process is targeted at 4%. The process is monitored daily by taking samples of sizes n=160 units. Suppose that today's sample contains 14 defectives. How many units would have to be sampled to be 95% confident ...
*Saturday, May 4, 2013 at 4:47pm*

**Statistics**

A certain lottery is won by selecting the correct four numbers from 1,2....30. The probability of winning if the rules are changed so that in addition to selecting the correct four numbers you must now select them in the same order as they are drawn?
*Saturday, May 4, 2013 at 3:37pm*

**Statistics**

The world’s smallest mammal is the bumblebee bat. Such bats are roughly the same size of a large bumblebee. Listed below are the weights (in grams) from a sample of these bats. Assuming that all such bats have a standard deviation of .3 grams, use a significance level of...
*Saturday, May 4, 2013 at 1:21pm*

**statistics**

A manufacturing company produces 10,000 plastic glasses per week. This company supplies plastic glasses to another company, which packages the glasses as part of picnic sets. The second company randomly samples 10 glasses from the supplier. If at least eight of the sampled ...
*Saturday, May 4, 2013 at 3:26am*

**Statistics**

The Education Testing Service conducted a study to investigate differences between the scores of males and females on the SAT. The study identified a random sample of 562 females and 852 males that had achieved the same high score on the math portion of the test. That is, both...
*Friday, May 3, 2013 at 10:40pm*

**statistics**

A firm having 4000 employees took a random sample of 25 in order to estimate their average annual state tax payment with 99% confidence. If the results were X = $640 and s = $20, what is the best interval estimation?
*Friday, May 3, 2013 at 10:37pm*

**Statistics**

For questions 1-5, write the null and alternative hypothesis. 1. Does the water temperature have an effect on the number of people in the pool? 2. Does the weather have an effect on the number of people at the beach? 3. A fitness center is running a discounted membership fee. ...
*Friday, May 3, 2013 at 11:47am*

**Statistics**

1. A study of 40 people found that they could do on the average15 pull ups with a standard deviation of .6. Find the 99% confidence interval for the mean of the population. 2. A study of 50 pizza delivery workers found that they could make 6 deliveries per hour with a standard...
*Friday, May 3, 2013 at 11:45am*

**statistics**

400 draws are made at random with replacement from 5 tickets that are marked -2, -1, 0, 1, and 2 respectively. Find the expected value of: 1. the number of times positive numbers appear 2. the sum of all the numbers drawn 3. the sum of the positive numbers drawn
*Friday, May 3, 2013 at 4:34am*

**Statistics**

One of your friends is comparing yeast fermentation rates when yeast is grown in a solution containing glucose (G) and when grown in a solution containing starch (S). The friend starts with no expectations about which feeding medium will give higher yields but after seeing the...
*Friday, May 3, 2013 at 3:39am*

**Statistics**

In planning a study of the birth weights of babies whose mothers did not see a doctor while pregnant, a researcher writes the hypotheses as H0: x̄ = 2250 grams versus H1: x̄ < 2250 grams. What is wrong with this?
*Friday, May 3, 2013 at 3:37am*

**statistics**

A sample survey interviews an SRS of 263 college women. Suppose (as is roughly true) that 75% of all college women have been on a diet within the past 12 months. Using the Normal approximation, what is the probability (±0.001) that 82% or more of the women in the sample...
*Thursday, May 2, 2013 at 10:48pm*

**statistics**

Linda Silbers is a social scientist studying voter opinion about a city bond proposal for a light rail mass transit system in Denver If Linda wants to be 90 percent Confident that her sample estimate of the proportion of voters who favor the bond is within 2 percent of the ...
*Thursday, May 2, 2013 at 9:35pm*

**Statistics**

Assuming that the heights of college women are normally distributed with mean 66 inches and standard deviation 2 inches, what percentage of women are shorter than 72 inches?
*Thursday, May 2, 2013 at 5:39pm*

**statistics**

researcher wants to know if state quarters have a weight that is mor than traditional quarters. he selected 18 state quarters and 16 traditional, weighed each of them and recorded data. test the claim that state quarters have a mean weight that is more than traditional ...
*Wednesday, May 1, 2013 at 11:52pm*

**statistics**

Paul received a score of 80 on a history test for which the class mean was 70 with a standard deviation of 10. He received a score of 75 on a biology test for which the class mean was 70 and the standard deviation was 2.5. On which test did he do better relative to the rest of...
*Wednesday, May 1, 2013 at 10:25pm*

**Statistics**

Use the sample data and confidence level to construct the confidence interval estimate of the population p....n=5200, x=4821, 99% confidence
*Wednesday, May 1, 2013 at 9:51pm*

**statistics**

In a survey of 1,000 people, 520 are opposed to the tax increase. Construct a 95% confidence interval for the proportion of those people opposed to the tax increase.
*Wednesday, May 1, 2013 at 9:54am*

**Statistics :(**

I have like 9 more of these problems, can someone please help me out so I can get started. thanx JS In a random sample of 35 tractors, the annual cost of maintenance was $4,425 and the standard deviation was $775. Construct a 90% confidence interval for this. Assume the annual...
*Wednesday, May 1, 2013 at 8:56am*

**Statistics**

In a sample of 77 widgets, 6 were defective. How many defective widgets would you expect in a sample of 616 widgets?
*Tuesday, April 30, 2013 at 3:53pm*

**Probability & Statistics**

Charmaine is looking at the rental car prices for Get You There Rental Car Company. The cost is based on how many miles you plan to drive the rental car. Use the list of rental prices to answer the questions 1- 5. Miles Cost 200 $80 600 $120 1000 $160 1400 $200 1800 $320 1) ...
*Tuesday, April 30, 2013 at 3:18pm*

**Probability & Statistics**

Charmaine is looking at the rental car prices for Get You There Rental Car Company. The cost is based on how many miles you plan to drive the rental car. Use the list of rental prices to answer the questions 1- 5. Miles Cost 200 $80 600 $120 1000 $160 1400 $200 1800 $320 1) ...
*Tuesday, April 30, 2013 at 3:16pm*

**Math - Intro to Statistics (High School)**

The average square footage in an apartment in a town is 1,800 square feet with a standard deviation of 120 square feet. The square footage is normally distributed. You randomly select 10 apartments in the town. What is the probability that the mean will be more than 1900 ...
*Tuesday, April 30, 2013 at 12:10pm*

**Statistics**

A study of 420,048 cell phone users found that 135 of them developed cancer of the brain or nervous system. prior to this study of cell phone use the rate of such cancer was found to be 0.0333% for those not using cell phones. Complete parts (a) and (b) a. use the sample data ...
*Tuesday, April 30, 2013 at 1:04am*

**Statistics**

Use the given data to find the minimum sample size required to estimate a population proportion or percentage. Margin of error: five percentage points; confidence level 90% from a prior study, ^p is estimated by the decimal equivalent 56% n= (Round up to the nearest integer)
*Tuesday, April 30, 2013 at 12:44am*

**Statistics**

Use the given data to find the minimum sample size required to estimate a population proportion or percentage. Margin of error: 0.06; confidence level 90% ^p and ^q unknown n= (round up to the nearest integer)
*Tuesday, April 30, 2013 at 12:38am*

**Statistics**

Use the sample data and confidence level to construct the confidence interval estimate of the population proportion p. n=500, x=350, 90% confidence ?<p<? (Round to three decimal places as needed.)
*Tuesday, April 30, 2013 at 12:35am*

**Statistics **

Assume that a random sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level. 95% confidence the sample size is 2096 of which 25%are successes The margin of E= (round to four decimal places ...
*Tuesday, April 30, 2013 at 12:29am*

**statistics**

a quiz consists of 30 true or false questions. if the student guesses on each question, what is the standard deviation of the number of correct answers
*Monday, April 29, 2013 at 7:15pm*

**Statistics**

the scoring of IQ tests is designed so that the scores of the test taking population are normally distributed with a mean of 100 and a standard dev of 15. what percent of the population have an IQ less than 92? how do i figure this out?
*Monday, April 29, 2013 at 11:21am*

**statistics**

Let X represent the outcome of a single roll of a fair die. Suppose you will win $2 if the outcome is either 2 or 5, and lose $1 otherwise. What are your expected winnings in 20 tosses?
*Monday, April 29, 2013 at 10:12am*

**statistics**

the probability that a house in an urban area will develop a leak is 5%. if 23 houses are randomly selected, what is the probability that none of the houses will develop a leak?
*Sunday, April 28, 2013 at 4:18pm*

**Statistics**

Suppose x has a mound-shaped distribution with sigma = 9 . A random sample of size 36 has sample mean 20. Is it appropriate to use a normal distribution to compute a confidence interval for the population mean m? Explain. Find a 95% confidence interval for m. Explain the ...
*Saturday, April 27, 2013 at 6:54pm*

**Life orientation**

Identify and describe three environmental health hazards that cause ill health ,crises ,and globally .include evidence that is current of the identified issues .use graph s,statistics,pictures etc to show evidence of your information.
*Saturday, April 27, 2013 at 2:07pm*

**Life orientation**

Identify and describe three environmental health hazards that cause ill health ,crises ,and globally .include evidence that is current of the identified issues .use graph s,statistics,pictures etc to show evidence of your information.
*Saturday, April 27, 2013 at 2:02pm*

**statistics**

A random sample of 100 of a population Mean is 31 and standard deviation 22 Approximate probability of 28
*Saturday, April 27, 2013 at 10:45am*

**statistics**

A convenience store owner believes that the median number of lottery tickets sold per day is 49. A random sample of 20 days yields the data below. Find the critical value to test the owner's claim. 32 48 59 64 31 55 70 27 33 38 47 54 54 44 44 49 49 59 54 38
*Friday, April 26, 2013 at 11:48pm*

**more statistics**

The percent of fat calories that a person in America consumes each day is normally distributed with a mean of 36 and a standard deviation of about 10. Suppose that 16 individuals are randomly chosen for an experiment. Completely describe the distribution of sample means for ...
*Friday, April 26, 2013 at 9:37pm*

**computer science**

What does it mean when there is a high prior probability in terms of Baynesian statistics?
*Friday, April 26, 2013 at 4:55pm*

**statistics**

An independent-measures research study computes three treatment conditions with a sample of n=10 in each conditions. The sample means are M1=2, m2=3, and m3=7. a. Compute SS for the set of 3 treatment means. (Use the three means as a set of n=3) scores and compute SS.)
*Friday, April 26, 2013 at 3:42pm*

**AP Statistics**

A school psychologist reports that the mean number of hours the students at this school sleep each night is 8 hours. The students believe the mean is not 8 hours. To find an estimate of the true mean, they select a random sample of 15 students from their school and ask how ...
*Friday, April 26, 2013 at 3:25pm*

**statistics**

A company produces batteries whose lifetimes are normally distributed with a mean of 100 hours. It is known that 90% of the batteries last at least 40 hours. (i). Estimate the standard deviation lifetime. (3 marks) (ii). What percentage of batteries will not last 70 hours?
*Friday, April 26, 2013 at 12:51pm*

**Psychology Statistics**

2 For a sample of n = 20 individuals, how large a Pearson correlation is necessary to be statistically significant for a two-tailed test with = .05? 3 The Pearson correlation is calculated for a sample of n = 25 individuals. What value of df should be used to ...
*Friday, April 26, 2013 at 8:19am*

**statistics**

The manager of a local gym has determined that the length of time members spend at the gym is a normally distributed variable with a mean of 80 minutes and a standard deviation of 20 minutes. What proportion of members spend less than 55 minutes at the gym? Use the standard ...
*Friday, April 26, 2013 at 5:30am*

**statistics**

out of ten questions two students got 8 wrong find out probability if they are cheating
*Thursday, April 25, 2013 at 9:46pm*

**Statistics**

A school is running a raffle. There are 100 tickets, of which 3 are winners. You can assume that tickets are sold by drawing at random without replacement from the available tickets. Teacher X buys 10 raffle tickets, and so does Teacher Y. Find the chance that one of those two...
*Thursday, April 25, 2013 at 5:05pm*

**Statistics**

To test H0: = 80 versus H1: < 80. a simple random sample of size n = 22 is obtained from a population that is known to be normally distributed. a) If ¯x = 76.9 and s = 8.5, compute the test statistic.
*Thursday, April 25, 2013 at 3:30pm*

**statistics**

All deal with a random variable X that follows a normal probability distribution with mean equal to 37 and a standard deviation of 5. Compute P(X < 39) Compute P(X < 29 or X > 41) Compute P(X > 30) Find the 42nd percentile for this distribution.
*Thursday, April 25, 2013 at 3:28pm*

**statistics**

All deal with a random variable X that follows a normal probability distribution with mean equal to 37 and a standard deviation of 5. Compute P(X < 39) Compute P(X < 29 or X > 41) Compute P(X > 30) Find the 42nd percentile for this distribution.
*Thursday, April 25, 2013 at 3:27pm*

**Statistics**

Find the binominal probability...n = 15, p = .04, find P(fewer than 3)
*Thursday, April 25, 2013 at 2:15pm*

**statistics**

The duration of time it takes General Motors to build a car is normally distributed with a mean of 31 hours and a standard deviation of 2 hours. a) What is the probability that a single car, selected at random, will take between 28 and 34 hours? b) What is the probability that...
*Thursday, April 25, 2013 at 1:42pm*

**statistics**

0.57 of all college students like the idea of a new curriculum. If we select 88 students (ASSUME INDEPENDENCE), what is the Standard Deviation of (the Probability Distribution that would list the number of students (from 0 to 88) and the probability of each.) THE STANDARD ...
*Wednesday, April 24, 2013 at 8:37pm*

**statistics**

A film alliance used a random sample of 50 U.S. citizens to estimate that the typical American spent 78 hours watching videos and DVDs last year. The standard deviation of this sample was 9 hours. (a) Develop a 95 percent confidence interval for the population mean number of ...
*Wednesday, April 24, 2013 at 8:02pm*

**statistics **

adult males have normally distributed heights with mean of 69.0 in and a standard deviation of 2.8 in. if a clothing manufacture decides to produce goods that exclude the shortest 12% and the tallest 12% of adult males, find the minimum and maximum heights that they will fit.
*Wednesday, April 24, 2013 at 6:22pm*

**statistics**

if no preliminary sample is taken to estimate p, how large a sample is necessary to be 87% sure that the point estimate will be within a distance of 0.04 from p?
*Wednesday, April 24, 2013 at 6:05pm*

**statistics**

Your mail-order company advertises that it ships 95% of its orders within three working days. You select an SRS of 100 of the 5000 orders received in the past week for an audit. The audit reveals that only 91 of these orders were shipped on time. A) What is the sample ...
*Wednesday, April 24, 2013 at 4:31pm*

**statistics**

A study of 36 marathon runners showed that they could run at an average rate of 7.8 miles per hour. The sample standard deviation is 0.6. Find a point estimate of the population mean. Find the 90% confidence interval forthe mean of all runners. Based on the results, what ...
*Wednesday, April 24, 2013 at 12:58pm*

**statistics**

Suppose that the test scores for a college entrance exam are normally distributed with a mean of 450 and a standard deviation of 100. If a student is selected at random what is the probability that the student will score above 600?
*Wednesday, April 24, 2013 at 11:36am*

**statistikc **

We want a confidence interval for the mean IQ of all the 7th grade girls in that school district. We do not know the population standard deviation so we use the confidence interval that uses the t. In order to use the t-interval we need to assume that the variable IQ has a ...
*Wednesday, April 24, 2013 at 11:15am*

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