Sunday

December 4, 2016
**Statistics**

Find the critical value za/2 that corresponds to a=0.12.

*Friday, November 20, 2015 by tyler *

**Behavioral Statistics Help!**

There are also potential problems associated with interpreting the results of a paired t-test. Imagine you are interested in determining whether an employee of a company performs better with or without a bonus. What are some issues that could affect the results if you have the...

*Friday, November 20, 2015 by slomomo*

**Statistics**

A survey of physicians in 1979 found that some doctors give a placebo to patients who complain of pain for which the physician can find no cause. If the patients' pain improves, these doctors conclude that it had no physical basis. The medical researchers who conducted the...

*Friday, November 20, 2015 by Tim*

**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. A) Is it appropriate to use the normal approximation for ...

*Thursday, November 19, 2015 by Brandy*

**statistics**

how even numbers greater than 40,000 may be formed using the digits 3,4,5,6,and 9 if each digit must be used exactly once in each number?

*Wednesday, November 18, 2015 by sharfun*

**Statistics**

An urn contains three yellow,four green and five blue balls. Two balls are randomly drawn without replacement. Find the probability of the following events: a.both balls are blue. b.the first ball is green and the second yellow. c.there is one green and one yellow ball

*Wednesday, November 18, 2015 by Dominiq*

**Statistics**

The weekly amount of gas sold at a self serve gas station has a uniform distribution on the interval 5000 to 15,000 gallons. If the dealer begins the week with 12,625 gallons in his supply tank what is the probability that he will run out of gas before the end of the week

*Monday, November 16, 2015 by Jackie *

**statistics**

The time needed to complete a final examination in a particular college course is normally distributed with a mean of 79 minutes and a standard deviation of 8 minutes. Answer the following questions. Assume that the class has 60 students and that the examination period is 90 ...

*Sunday, November 15, 2015 by margaret*

**Maths **

Statistics The marks scored by a sample of 56 students are summarised by: N=56 Sum of x =3026 sum of(x-the mean)^2 =15378 A) calculate the mean and the standard deviation Mean I got - 54.04 (2.dp) Standard deviation I got - 16.72 (2.dp) Is this correct? B) the formula y=1.2x-...

*Sunday, November 15, 2015 by Anonymous *

**statistics **

in a lottery, a player wins or shares in the jackpot by selecting the correct 6-number combination when six different numbers from 1 through 49 are drawn. if a player selects one particular 6-number combination, find the probability of winning the jackpot.

*Sunday, November 15, 2015 by safi*

**Maths**

Statistics The marks scored by a sample of 56 students are summarised by: N=56 Sum of x =3026 sum of(x-the mean)^2 =15378 A) calculate the mean and the standard deviation Mean I got - 54.04 (2.dp) Standard deviation I got - 16.72 (2.dp) Is this correct? B) the formula y=1.2x-...

*Sunday, November 15, 2015 by Anonymous *

**business statistics **

A sample of 900 items is taken from a population with standard deviation 15. The mean of the sample is 25. Test whether the sample has come from a population with mean 26.8. Take a=5%

*Saturday, November 14, 2015 by Isaac *

**Statistics**

Use normal approximation to find the probability of the indicated number of voters. In this case, assume that 184 eligible voters aged 18-24 are randomly selected. Suppose a previous study showed that among eligible voters aged 18-24, 22% of them voted. Probability that fewer ...

*Saturday, November 14, 2015 by Tralala*

**Statistics**

Create a null hypothesis or the following research questions: (a) What are the differences between emergency room shifts on medication errors? (b) On a clinical trail of a new drug, what will be the effects over a currently used drug?

*Friday, November 13, 2015 by Sharon*

**Statistics Help!**

An insurance company asks you to determine whether older drivers are safer than younger ones. Provide a directional hypothesis related to this study. Then, explain how you would need to change the hypothesis so that it would be non-directional. What happens to the rejection ...

*Thursday, November 12, 2015 by Bradman*

**Statistics **

the length of times it takes college students to find a parking spot im the library parking lot follows a normal distribution with a mean of 5.5 minutes and a standard deviation of 1 minute. find the cut off time which 75.8% of the college students exceed when trying to find a...

*Thursday, November 12, 2015 by Cody*

**statistics**

A student has a mean score of five tests taken. What score must she obtain on her next test to have a mean average of 88 on all six tests?

*Thursday, November 12, 2015 by ivy*

**Statistics Help Please!**

When computing a t-test, it is important to distinguish between directional and nondirectional hypotheses as the direction will determine the rejection regions. Describe how the rejection regions would differ according to the type of hypothesis you would use.

*Thursday, November 12, 2015 by Bradman*

**business math and statistics**

in the formula for calculating present value the letter R represent the

*Wednesday, November 11, 2015 by Anonymous*

**Statistics**

10. A teacher gives 200 students a study guide for a test and the average score was 90 with a standard deviation of 6. She did not give the other 200 students a study guide and their average score was 70 with a standard deviation of 8. Find the critical value to determine ...

*Wednesday, November 11, 2015 by Bert*

**Statistics**

10. A teacher gives 200 students a study guide for a test and the average score was 90 with a standard deviation of 6. She did not give the other 200 students a study guide and their average score was 70 with a standard deviation of 8. Find the critical value to determine ...

*Wednesday, November 11, 2015 by Bert*

**Statistics**

We observe a sample proprotion p-hat = 0.3. If the standard deviation of the sampling distribution of p-hat is 0.04, what is the 95% confidence interval for p?

*Tuesday, November 10, 2015 by Morgan*

**Statistics**

A marketing research firm wishes to determine if the residents of Caldwell, Idaho, would be interested in a new downtown restaurant. The firm selects a simple random sample of 120 phone numbers from the Caldwell phone book and calls each household. Only 62 of those called are ...

*Monday, November 9, 2015 by Kevin*

**Statistics**

Researchers wish to determine if a new experimental medication will reduce the symptoms of allergy sufferers without the side-effect of drowsiness. To investigate this question, the researchers give the new medication to 50 adult volunteers who suffer from allergies. Forty-...

*Monday, November 9, 2015 by Kevin*

**Statistics**

For a certain computer program a password must be exactly 5 characters long the first character must be a number 0-5, the second third and fourth character can either be one of the 26 letters or a number 0-9, the fifth character has to be exactly the same as the second ...

*Monday, November 9, 2015 by Sawyer James*

**Statistics**

Team X has an average (mean) height of 70 inches and a standard deviation of 3 inches and Team Y has an average height of 67 inches with a standard deviation of 9 inches. Compare the two teams using this information and which team will have the tallest and shortest player ...

*Sunday, November 8, 2015 by Becky*

**Statistics and probability**

A psychologist tested the IQ in a sample of 36 children. Their mean IQ was 104. What is the probability of getting an IQ score of 104 or higher? The mean is 100, and the standard deviation is 15

*Sunday, November 8, 2015 by Echell*

**please give me a site or answer!!!!**

description of the population statistics LOCATION in South Carolina already found the age and race just having trouble with the location statistics please help!!!!!!

*Sunday, November 8, 2015 by Anonymous*

**Statistics**

A bag contains 5 purple marbles, 7 yellow marbles, and 3 orange marbles. If two marbles are selected from the bag: What is the probability that an orange then a yellow are chosen with replacement?

*Saturday, November 7, 2015 by Kate*

**Statistics**

What is the probability of randomly selecting a red marble from a jar that contains 10 red marbles and 20 blue marbles?

*Wednesday, November 4, 2015 by Bradman*

**Statistics**

Describe a situation in which you would test a directional hypothesis. Be sure to state the independent variables (e.g., drug or placebo) and the dependent variables (e.g., weight loss) clearly and explain why the hypothesis is directional. Then, revise the same situation to ...

*Tuesday, November 3, 2015 by Bradman*

**statistics**

when figuring mode, mean and median do you add all the like figure such as days and no. of discharges? you don't just add all the numbers up together right?

*Monday, November 2, 2015 by Anonymous*

**Statistics**

Directional and non-directional hypotheses can be easily interchanged according to the hypothesis the researcher is testing. For instance, a drug company might predict that a drug will help a subject lose weight while another drug company might predict that a drug will alter a...

*Monday, November 2, 2015 by Slomo*

**Health statistics **

An employee currently earning $13.85 per hour has been awarded a 3.5 percent merit raise. What will gge employee's hourly salary be with this increase. 13.85x3.5=48.475 is what I'm thinking

*Sunday, November 1, 2015 by Anonymous *

**statistics**

An exam is standardized to a Normal model, with a mean of 105 and a standard deviation of 18. Based on the Normal model N(105, 18) What exam score represents the 96th percentile? What percentile of an exam score of 100 represent?

*Sunday, November 1, 2015 by Anonymous*

**Statistics**

The following are Exam scores for a group of Mathematics students. a) Group this data by using the Sturges’ formula to determine the number of classes. Keep the width of each class equal. b) Find the mean, standard deviation and variance of the grouped data obtained in (a...

*Friday, October 30, 2015 by Fala*

**Probability and Statistics**

In a toy manufacturing company three machines A,B and C are employed to manufactures toys. Machines A, B and C manufacture 20%, 30% and 50% of the total toys respectively. A quality control officer examined the machines and found that A,B and C produce 2%, 3% and 5% defectives...

*Thursday, October 29, 2015 by Question*

**statistics **

one of the points in a set of points if (4,8). What is the residual for this point if the equation of the regression line for these points is y=3.6+1.8x

*Thursday, October 29, 2015 by Anonymous*

**English**

In the story "A Contribution to Statistics" 1.) Which of the following words best describes the author's view of humanity? a.) altruistic b.) optimistic c.) pessimistic d.) realistic my answer is a

*Thursday, October 29, 2015 by Steve*

**Statistics and probability **

In a town the probability that an inhabitant catches malaria in any month is 0.2A farm in the town employed 15 local people Find the mean and variance of the number of employees catching malaria

*Thursday, October 29, 2015 by Eryk*

**Statistics**

Find the indicated probability: P(z<0.18 or z>2.13) I'm stumped and can't find material on how to do this anywhere. I can do something like P(0.18>z<2.13) but not this. PLEASE HAAALLLP!

*Thursday, October 29, 2015 by Josh*

**Statistics HELP!!**

Identify an example of a population that you would expect to be normally distributed. Explain why, according to you, it would be normally distributed. Then, describe a subset of the population you identified and explain why it would not be normally distributed and what the ...

*Wednesday, October 28, 2015 by slomomo*

**statistics **

what is the difference between the coefficient of determination and residuals

*Wednesday, October 28, 2015 by Anonymous*

**Statistics**

A certain type of artificial heart has four independent, critical components.Failure of any one of these components is a serious problem that will cause the artificial heart to fail. The 5 year failure rate for each component follows: component 1=.02, component 2=.05, ...

*Wednesday, October 28, 2015 by Brandy*

**Statistics - PLEASE HELP!**

For a lottery game, each ticket has a probability of 1 / 3.09 = 0.324 of winning a prize. Every friday you buy 1 lottery game. a) What is the probability you will win on two of your next three games?

*Wednesday, October 28, 2015 by Lucie*

**Behavioral Statistics Help!**

The majority of the data is normally distributed if there are enough subjects. For instance, if you collected test scores of only a few honor students, the data will most likely not be normally distributed because you would have a sample that did not represent the entire ...

*Wednesday, October 28, 2015 by slomomo*

**Behavioral Statistics**

Let's say that the standardized test had 100 possible points. If we wanted to identify the top 25%, why not just select those with raw scores above 75? Why do we have to standardize the scores?

*Tuesday, October 27, 2015 by slomomo*

**Geography**

What country has similar statistics to Sweden

*Tuesday, October 27, 2015 by Geo*

**History**

Haiti and Cuba are relatively close to each other. What is your theory on why their population statistics are so different?

*Tuesday, October 27, 2015 by Geo*

**statistics**

all patients who present to the emergency services department with a suspected acute myocardial infraction are expected to receive an ECG within ten minutes of their arrival. Of the 56 patients who had a suspected AMI during the last quarter, 32 had an ECG within the specified...

*Monday, October 26, 2015 by Anonymous*

**statistics**

An internal study by the Technology Services department at Lahley Electronics revealed company employees receive an average of two emails per hour. Assume the arrival of these emails is approximated by the Poisson distribution. a. what is the probability that Linda Lahey, ...

*Monday, October 26, 2015 by sania*

**statistics**

In a large Midwestern university, 30% of the students live in apartments. If 200 students are randomly selected, find the probability that the number of them living in apartments will be between 55 and 70 inclusive.

*Monday, October 26, 2015 by Dabney*

**Behavioral Statistics**

Let's say that the standardized test had 100 possible points. If we wanted to identify the top 25%, why not just select those with raw scores above 75? Why do we have to standardize the scores?

*Sunday, October 25, 2015 by slomomo*

**Statistics**

A sample of n = 25 scores has a mean of M = 40 and a variance of s2 = 100. If this sample is being used to test a null hypothesis stating that m = 43, then what is the t statistic for the sample

*Sunday, October 25, 2015 by Ann*

**Statistics**

The same supervisor in the scenario above agreed to increase the salary of the employee to $15.00 per hour once she passed her RHIT exam. Three months after beginning her employment , the employee passed her RHI exam. What will the new budget be for salary and fringe benefits?

*Friday, October 23, 2015 by Sharon*

**Behavioral Statistics**

Explain the general rationale behind using a z-score for describing how an individual performed on an exam compared to just stating the overall mean and the individual's score. How does the information differ in the two situations? What additional information are you ...

*Thursday, October 22, 2015 by slomomo*

**Behavioral Statistics**

Imagine you are in charge of reviewing applications for your academic institution. As a preliminary measure, you want to review only the top 25% of applicants on the basis of standardized test scores. How does calculating the z-score provide additional information regarding ...

*Thursday, October 22, 2015 by Slomo*

**Math/Probability/Statistics**

Find the expected value and the standard deviation in the following raffle: Value Tickets Grand Prize: $2,000.00 1 Second Place Prize: $800.00 20 Third Place Prize: $40.00 60 Fourth Place Prize: $30.00 300 Total Number of Tickets Sold: 10000

*Thursday, October 22, 2015 by Anonymous*

**Statistics**

the heights of young women are approximately Normal with 65 inches and standard deviation 2.5 inches. The heights of men in the same age group have mean 70 inches standard deviation 2 inches. What percentage of women are taller than a man of average (mean) height?

*Wednesday, October 21, 2015 by Tay*

**Statistics**

A restaraunt offers a dinner special that lets you choose from 10 entrees, 8 side dishes, and 13 deserts. You can choose one entree, two side dishes, and one desert. How many different meals are possible?

*Wednesday, October 21, 2015 by Sam*

**statistics**

Two cards are drawn from a well-shuffled ordinary pack of 52 cards. The first card is replaced before selecting the second card. Find the following probabilities. (iii) One is King and one is queen (iv) Both are faced cards

*Wednesday, October 21, 2015 by usman*

**Statistics**

At the end of the Halloween Festival the organizers estimated that a family of participants spent an average $45.00 with a standard deviation of $12.00. What’s the probability that the mean amount spent will be between $20 and $30?

*Wednesday, October 21, 2015 by Karen*

**statistics**

Mamma temte bakes six pies a day that cost $2. on 15% of the days she sells 3 pies, on 30% of the days she sells 4. On 55% of the days she sells six pies, if mama temte sells her pies for $6 each, what is her expected profit for a days worth of pies?[assuming extras will be ...

*Wednesday, October 21, 2015 by Anonymous*

**Statistics**

a bag of colored marbles holds 71 yellow marbles and 70 white marbles. ten marbles are randomly selected, one at a time, without replacement. what is the probability that more than half are yellow?

*Monday, October 19, 2015 by Renee*

**Statistics**

A family consists of ten children. Assuming that the sexes are equally probable, find the expected number of boys in the family. What is the probability that the expected number of boys will not occur? (Not sure where to start) I got partial credit and I answered 5 (Question ...

*Monday, October 19, 2015 by Megan*

**Statistics**

It is estimated that heights of adult men are normally distributed with a mean of 70 inches and a standard deviation of 3.5. In one state, the law requires a person to be 68 inches or taller to become a fire fighter. (a) What proportion of adult men will meet this height ...

*Monday, October 19, 2015 by Erin*

**Statistics**

The height of a tree will be measured using a clinometer. For this device, the measurement error has a normal distribution with mean μ=0.00 meter and standard deviation σ=0.05. If the tree is exactly 30 meters tall, what is the probability that the clinometer will ...

*Monday, October 19, 2015 by Emily*

**Statistics **

The retail price of 12-pack soda can be characterized as having a normal distribution with a mean of 3.05 dollars and a standard deviation of 0.24. Below what price do you find 40 percent of all 12-packs?

*Monday, October 19, 2015 by Justine *

**statistics**

The experience of a certain hospital showed the the distribution of length stay of patients is normal with a mean of 11.5 days and a standard deviation of 2 days. a. What percentage of the patients stayed nine days or less? b.If a new method of nursing care is to be ...

*Sunday, October 18, 2015 by maica*

**Statistics**

At a certain university, 50% of all entering freshmen planned to major in a STEM (science, technology, engineering, mathematics) discipline. A sample of 36 freshmen is selected. What is the probability that the proportion of freshmen in the sample is between 0.475 and 0.580? ...

*Sunday, October 18, 2015 by Obi*

**Statistics**

74% of freshmen entering public high schools in 2006 graduated with their class in 2010. A random sample of 81 freshmen is selected. Find the probability that the proportion of students who graduated is greater than 0.750 . Write only a number as your answer. Round to 4 ...

*Sunday, October 18, 2015 by Obi*

**Statistics**

It has been reported that 48% of teenagers play video games on their phones. A random sample of 60 teenages is drawn. Find the probability that the proportion of teenagers in the sample who play videos games on their phone is less than 0.499 . Write only a number as your ...

*Sunday, October 18, 2015 by Obi*

**Statistics**

According to one pollster, 48% of people are afraid of flying. Suppose that a sample of size 20 is drawn. Find the value of standard error , the standard deviation of the distribution of sample proportions. Write only a number as your answer. Round to two decimal places (for ...

*Sunday, October 18, 2015 by Obi*

**Statistics**

At a certain concert, 43% of the audience was under 20 years old. A random sample of n = 181 members of the audience was selected. Find the value of sample mean, the mean of the distribution of sample proportions. Write only a number as your answer. Do not write as a percentage.

*Sunday, October 18, 2015 by Obi*

**Psychological Statistics**

A professor records scores from a five-point quiz for each student in an introductory psychology class. If the data were presented in a frequency distribution graph, what type of graph should be used?

*Friday, October 16, 2015 by Jay*

**statistics**

You are part of a school and have to report the results of standardized test scores. Which measure of central tendency would you use? Assume that you don't know how your students will perform; so consider the general effects of outliers on the three measures of central ...

*Thursday, October 15, 2015 by slomomo*

**statistics**

how we compare three different standard deviations

*Thursday, October 15, 2015 by shekhar*

**Statistics**

for a population with m=62 and s=12, find the x value that corresponds to esch of the following z-scores: -0.25,-1.50,0.50,2.00

*Wednesday, October 14, 2015 by Gloria*

**Statistics**

n=13 p=0.75 p (more than 11)

*Wednesday, October 14, 2015 by Jen*

**math statistics**

Convert Ken's chest, waist, and hips measurements to z-scores. Which of these measures appears to be the most different from kens reference group(human males)? Justify with an appropriate statistical argument. Ken's chest=75.0,waist=56.5,hips=72.0 Human x-bar chest is ...

*Wednesday, October 14, 2015 by zan*

**Statistics**

Suppose that the weight of male babies less than 2 months old is normally distributed with mean 11.5 pounds and standard deviation 2.7 pounds. A sample of 36 babies is selected. What is the probability that the average weight of the sample is less than 11.07 pounds? Write only...

*Wednesday, October 14, 2015 by Obi*

**Statistics**

Find the z-score for which the area to its left is 0.46 . Write only a number as your answer. Round to two decimal places (for example: 0.81).

*Tuesday, October 13, 2015 by Obi*

**Statistics**

Find the z-score for which the area to its right is 0.65 . Write only a number as your answer. Round to two decimal places (for example: 0.81).

*Tuesday, October 13, 2015 by Obi*

**Statistics**

The z-scores that bound the middle 35 % under the standard normal curve are z = -a and z = a. Find the value of a. Write only a positive number as your answer. Round to two decimal places (for example: 0.81).

*Tuesday, October 13, 2015 by Obi*

**Statistics**

Find z 0.44 . Write only a number as your answer. Round to two decimal places (for example: 0.81).

*Tuesday, October 13, 2015 by Obi*

**statistics**

a bag contains 10 red balls and 7 blue balls.a ball is drawn at random.the probability that ball drawn is red is

*Monday, October 12, 2015 by ahsan*

**STATISTICS**

A salesperson contacts eight potential customers per day. From past experience, we know that the probability of a potential customer making a purchase is .05. b.) What is the probability the salesperson will make exactly two sales in a day? this is what I think the answer is 0...

*Friday, October 9, 2015 by Anna*

**Math / Statistics**

{ In a recent basketball game, a player who makes 65% of his free throws made eight consecutive free throws. Assuming that free-throw shots are independent, determine whether this feat was unusual. } I'm just a little lost on how to determine if it's unusual or not. I ...

*Friday, October 9, 2015 by Mira*

**Statistics**

A researcher is studying the effects of caffeine on exam scores of college students. In this study: What would be the population and sample of this research? Extrapolate your views of the advantages and disadvantages of samples and populations to this example. Why would the ...

*Friday, October 9, 2015 by Slomo*

**statistics**

why and what dothese answers mean 29th percentil greater than 30th percentile

*Friday, October 9, 2015 by laurie parker*

**Probability and Statistics**

In the game of euchre, the deck consists of the 9, 10, jack, queen, king and ace of each suit. Players are dealt a five card hand. What is the probability that a player is dealt 3 hearts?

*Thursday, October 8, 2015 by Alissa*

**Statistics**

Do the samples appear to be from the same population? Why or why not? Support your answer with numerical facts and convincing reasons and explanations Chemical distribution stats: Five # summary: (2.29816, 2.29869, 2.299152, 2.30074) Mean: 2.299706 Standard deviation: 0.001313...

*Thursday, October 8, 2015 by Ashley*

**statistics**

: Two cards are drawn from a well-shuffledordinary pack of 52 cards. The first card is replaced before selecting the second card. Find the following probabilities. (i) Both are kings (ii) First is king and second is queen (iii) One is King and one is queen (iv) Both are faced ...

*Thursday, October 8, 2015 by ahsan*

**statistics**

A student takes an exam containing 14 multiple choice questions. The probability of choosing a correct answer by knowledgeable guessing is 0.5. At least 9 correct answers are required to pass. If the student makes knowledgeable guesses, what is the probability that he will ...

*Thursday, October 8, 2015 by donna*

**statistics**

supposed that two balanced dice are rolled. let Y denote the product of the two numbers. use random variable notation to represent the event that the product of the two numbers is greater than 4 a {5,6} b {XY>4} c{Y>4} d P(Y>4)

*Wednesday, October 7, 2015 by A*

**statistics**

2. Find the variance and standard deviation of the following sample. 0 -5 -3 6 4 -4 1 -5 0 3

*Wednesday, October 7, 2015 by omar*

**AP Statistics**

Do the samples appear to be from the same population? Why or why not? Support your answer with numerical facts and convincing reasons and explanations Chemical distribution stats: Five # summary: (2.29816, 2.29869, 2.299152, 2.30074) Mean: 2.299706 Standard deviation: 0....

*Wednesday, October 7, 2015 by Ashley*

**Statistics**

STATISTICS: I'm struggling with how to calculate the following problems: *Assume that X~N(3,1.5) For what value of X is Pr(x<K) = 50% *Assume that X~N(3,1.5) What value of X would be equal to a z-score of -2? *Assume that X~N(3,1.5) Find the 90% percentile *Assume X~N(4...

*Wednesday, October 7, 2015 by BONACA*

**Statistics**

1. If P(A) = 0.4 P(B) = 0.2 and P(A or B) = 0.5, find the sum of P(A and B) and P(A|B). -How would I even start this question? 2. Let A and B be two mutually exclusive events for which P(A) = 0.15 and P(B) = 0.3. Find P(A and B). -If it's mutually exclusive, wouldn't ...

*Tuesday, October 6, 2015 by Alex*

**Statistics**

According to one survey, the mean serum cholesterol level for U.S. adults was 195.1, with a standard deviation of 41.5. A simple random sample of 95 adults is chosen. Find the 46 percentile for the sample mean. Write only a number as your answer. Round to one decimal places.

*Tuesday, October 6, 2015 by Tommy*