Friday

November 21, 2014

November 21, 2014

Number of results: 73,340

**statistics**

The average teenager spends 7.5 hours per week playing computer and video games. In a random sample of 110 teenagers, what is the probability that their mean time for playing games is more than 8 hours per week?
*November 2, 2011 by ron*

**Math**

Your parents allow you to play video games for no more than 8 hours a week. You have already played for 2.5 hours this week. Write and solve an inequality that represents how much more time you can play video games this week. Graph the solution on a number line.
*May 13, 2013 by Bell*

**statistics**

To determine how many hours per week freshmen college students watch television, a random sample of 225 students was selected. It was determined that the students in the sample spent an average of 35 hours watching TV per week. The population standard deviation is known to be ...
*May 6, 2012 by M.C*

**stats**

A research firm conducted a survey to determine the mean amount people spend at a popular coffee shop during a week. They found the amounts spent per week followed a normal distribution, with a population standard deviation of $4. A sample of 49 customers revealed that the ...
*November 4, 2014 by Anonymous*

**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 ...
*April 24, 2013 by Anonymous*

**algebra**

3.Your parents allow you to play video games for no more than 8 hours a week. You have already played for 2.5 hours this week. Write and solve an inequality that represents how much more time you can play video games this week.
*May 17, 2013 by me*

**statistics**

A sample of 352 subscribers to Wired magazine shows the mean time spent using the Internet is 13.4 hours per week, with a sample standard deviation of 6.8 hours. Find the 95 percent confidence interval for the mean time Wired subscribers spend on the Internet.
*March 19, 2012 by Annette*

**statistics**

A survey was conducted to measure the number of hours per week adults spend on home computers. In the survey, the number of hours was normally distributed, with a mean of 8 hours and a standard deviation of 1 hour. A survey participant is randomly selected. Find the ...
*November 7, 2011 by lindsay*

**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 ...
*April 26, 2013 by Anonymous*

**STATISTICS**

A statistics professor conducted a study on the effect of playing video games on a student’s test scores. On the first day of class, she randomly divided her classes into groups. Group one played video games 2 hours a day, group two played video games 4 hours a day, and group ...
*February 5, 2011 by DEBBIE*

**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
*June 6, 2012 by Julio*

**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
*June 6, 2012 by Julio*

**agebra**

Sam and Chris went to “Lots O Fun” to play laser tag and video games for Chris’s birthday. Sam played 3 games of laser tag, 5 video games, and spent $17 total. Chris played 4 games of laser tag, 7 video games, and spent $23 total. How much does one video game cost to play?
*November 5, 2010 by Mariel*

**Math**

A college student decides that school work limits him to a total of no more than 36 hours per week at his two parttime jobs. He earns $6 per hour hanging wall paper and he has a sales job that pays $8 per hour. He needs to earn at least $245 per week to cover his expenses. ...
*February 21, 2013 by T-perry*

**math**

haris has 20.92 to spend on videos-games rentals at a local video store. the store charges 3.95 per video-game rental plus 8.125% tax. what is the maximum number of video games that harris can rent?
*June 25, 2008 by kenneth mitchell*

**linear optimization**

During a summer session a student enrolls in two courses, psychology for four hours and engineering for three hours. The student wants to use the available time to amass the largest number of grade points (numerical grade multiplied by the number of hours). Students who have ...
*December 29, 2013 by gemicia*

**Math**

A student ears $10 per hour for tutoring and $7 dollars per hour as a teacher's aid. Let x= number of hours each weeks spent tutoring and y=the number of hours each week spent as teacher's aid. Write the objective function that describes the total weekly earnings: e=10x+7y ...
*May 9, 2011 by pele*

**Reading**

Dear Editor, 1 In your recent article "Just a Play Day," you argue that playing video games is a waste of time. You also descrive video-game players as lazy young people who loaf for hours in front of a screen. I respectfully disagree with your opinions. I would like to offer ...
*March 20, 2012 by running.from.myself*

**Reading**

Dear Editor, 1 In your recent article "Just a Play Day," you argue that playing video games is a waste of time. You also descrive video-game players as lazy young people who loaf for hours in front of a screen. I respectfully disagree with your opinions. I would like to offer ...
*March 20, 2012 by running.from.myself*

**Statistics **

Let’s suppose a randomly selected sample of 75 American teenagers watches an average of 1472 hours of television per year with a standard deviation of 250 hours. Construct the 95% confidence interval (CI) for the mean number of hours American teenagers watch television per year
*November 7, 2012 by Olivia*

**Statistics**

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. Use the data to construct a 90% ...
*February 12, 2014 by Stephanie*

**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 ...
*July 7, 2012 by Desperate *

**statistics**

A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 13 hours, with a standard deviation of 2.5 hours. It is desired to estimate the mean viewing time within two-quarter ...
*September 13, 2014 by Anonymous*

**Math**

John has two part time jobs. He works no more than 40 hours per week. He earns $6 per hour from the first job and $8 per hour from the second job. To cover his expenses, he needs to earn at lease $210 per week. Which of the following system of linear inequalities shows the ...
*May 14, 2012 by Shadia*

**statistics**

Suppose that in the aerobic exercise group we also measured the number of hours of aerobic exercise per week and the mean is 5.2 hours with a standard deviation of 2.1 hours. The sample correlation is -0.42. a)Is there evidence of a significant correlation between number of ...
*November 26, 2011 by natasha*

**Statistics**

A random sample of 47 students studied for an average of 7.1 hours last week. If the population standard deviation is 1.2 hours, what is the 90% confidence interval for the population mean?
*April 18, 2014 by Monica*

**statistics**

Undergraduates in a large university class were asked to record the time they spent on the most recent homework. In a histogram of the recorded times, the height of the bar over the interval “1 hour to 3 hours” is 4% per hour. The height of the bar over the interval “3 hours ...
*March 28, 2013 by TT*

**biostatistics**

7. Consider again the data in problem #6. Suppose that in the aerobic exercise group we also measured the number of hours of aerobic exercise per week and the mean is 5.2 hours with a standard deviation of 2.1 hours. The sample correlation is -0.42. a)Is there evidence of a ...
*November 26, 2011 by natasha*

**statistics**

A medical board claim that the mean number of hours worked per week by surgical faculty who teach at an academic institution is more than 60 hours. A random sample of 7 surgical facility has a mean hours worked per week of 70 hours and a standard deviation of 12.5 hours. At a=...
*May 10, 2012 by Jessie *

**stats**

1. A confidence interval can be calculated to estimate the population mean when the population is normally distributed or the sample size is greater than 30. Can a confidence interval be calculated for the average number of hours of sleep for the US babies using this ...
*October 14, 2014 by morgana*

**statistics**

Before 33 33 38 33 35 35 40 40 40 31 After 34 28 25 28 35 33 31 28 35 33 Ten different families are tested for the number of gallons of water per day they use before and after viewing a conservation video. Construct a 90% confidence interval for the mean of the differences.
*November 28, 2011 by jabrony*

**Algebra 2**

the demand for a new video game is given by the function p(x)= -x^2 + 5x +75. Correspondingly, the supply function for the same game is given by p(x) = 7x-9, where p represents the price per video in dollars and x represents the number of video games sold in thousands of games...
*May 30, 2011 by someone*

**psy**

)]}> Many are concerned that playing violent games may lead to violent behavior. However, statistics show that violent behavior in children has declined significantly at the same time that video game sales have skyrocketed. It is therefore clear that there is no ...
*September 25, 2010 by Cat*

**statistics**

Which interval describes the number of hours spent studying in a typical week for about 50% of the students sampled? 2 to 9 9 to 14 9 to 20 14 to 20 A five number summary of respones is: 2,9, 14, 20, 60
*September 2, 2014 by Jeannie*

**algebra-word problem**

2001-2005 number hours user spent on the internet each week increased 110% by hours. This percent increased amount to 11 hours. Find the average number of hours that a user spent on the internet in each week in 2001 and 2005. Having problems with setting it up.
*April 22, 2013 by Deb*

**math**

In a time-use study, 20 randomly selected managers were found to spend a mean of 2.40 hours each day on paperwork. The standard deviation of the 20 scores is 1.30 hours. Also, the sample data appear to have a bell-shaped distribution. Construct the 95% confidence interval for ...
*July 29, 2012 by becky*

**Statistics**

A random sample of 90 observations produced a mean that = 25.9 and a standard deviation s =2.4 (a)Find a 95% confidence interval for u (b)Find a 90% confidence interval for u (c)Find a 99% confidence interval for u (Use integers or decimals for any number in the expression. ...
*March 23, 2014 by Carol Harper*

**Statistics**

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a standard deviation of 6 hours, what is the required sample size if the error is to be less than ½ hour with a ...
*December 8, 2008 by Zenna*

**Math**

At the start of the week, the amount of money in Howard's bank account varies directly with the number of hours he worked and inversely with the number of hours he spent shopping the past week. If has $2,000 in his bank account the week after spending 25 hours working and 4 ...
*September 20, 2013 by Anonymous*

**Statistics**

A confidence interval for a population mean has a margin of error of 3.1. a)Determine the length of the confidence interval. b)If the sample mean is 56.7, obtain the confidence interval.
*May 21, 2014 by Anonymous*

**Statistics**

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a standard deviation of 3 hours, what is the required sample size if the error should be less than ½ hour with a ...
*September 5, 2010 by Robin*

**Math**

Let h represent the number of hours Shaunda spent on homework last week. 1.Zach spent half as much time on his homework as shaunda had on hers.Write an expression for the number of hours he spent.
*December 1, 2010 by ursula*

**Statistics 3**

A student union wants to obtain a 90% confidence interval for the proportion of “full time” students who hold a part-time job for 20 hours or more per week. For this purpose, they want to interview a sample of full-time students. They want a margin of error to be at most 0.1, ...
*December 16, 2013 by Steven *

**statistics 3.**

A student union wants to obtain a 90% confidence interval for the proportion of “full time” students who hold a part-time job for 20 hours or more per week. For this purpose, they want to interview a sample of full-time students. They want a margin of error to be at most 0.1, ...
*December 17, 2013 by Steven *

**statistics 3.**

A student union wants to obtain a 90% confidence interval for the proportion of “full time” students who hold a part-time job for 20 hours or more per week. For this purpose, they want to interview a sample of full-time students. They want a margin of error to be at most 0.1, ...
*December 17, 2013 by Steven *

**statistics**

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of 6 hours, what is the required sample size if the error should be less than ½ ...
*July 22, 2012 by Anonymous*

**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...
*May 9, 2013 by Anonymous*

**math/algebra**

Can I get help in solving these problems using the linear system of elimination. 4x - 5y =22 x + 2y = -1 2x - 3y = 16 3x + 4y = 7 Word Problem: During the summer, you want to earn at least $150 per week. You earn $10 per hour working for a farmer and you earn $5 per hour ...
*March 12, 2009 by JAY10*

**statistics**

Question 6: A manufacturer knows that the number of items produced per hour by its two factories A and B is normally distributed with standard deviations 8.0 and 11.0 items respectively. The mean hourly amount produced by Firm A from a random sample of 50 hours is 120 units ...
*April 12, 2012 by molebogeng*

**math**

danielle plays softball and basketball. however because she like basketball more, she spends 3 times as long playing basketball than she does playing softball. if she spends 18 hours a week playing these sports, how much time does she devote tp playing basketball? a)13 hours b...
*December 31, 2012 by paula*

**Statistics**

A survey among freshmen at a certain university revealed that the number of hours spent studying the week before final exams was normally distributed with mean 25 and standard deviation 15. A sample of 36 students was selected. What is the probability that the average time ...
*June 20, 2013 by Anonymous*

**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?
*June 18, 2012 by tristen*

**Statistics 2**

The body temperature of healthy human beings can be assumed to have a normal distribution with mean and standard deviation . Body temperature measurements taken from a sample of 130 healthy individuals shows the sample mean temperature to be 98.249O F and ...
*December 16, 2013 by Steven *

**RES 341**

A sample of 300 is taken and the sample mean is computed to be 7.65 and the sample standard deviation is 5. Assume the data is ratio level. Compute the 95% confidence interval on the mean. Compute the 3.9% confidence interval on the mean Which confidence interval is more ...
*October 16, 2010 by Meh*

**Math**

In 1 week, the hours worked by the 6 cashiers at buy and fly were 20,20,29,48,52, and 56. Would using the mean or the median number of hours encourage a person who wants at least 35 hours per week to apply for a job at buy and fly? Explain?
*December 7, 2011 by Frances*

**Statistics**

A study was conducted to estimate the mean amount spent on Christmas gifts for a typical family having two children. A sample of size 150 was taken, and the mean amount spent was $225. Assuming a standard deviation equal to $50, find a 95% confidence interval for , the mean ...
*November 18, 2008 by Kennon*

**Statistics**

Biologists studying the healing of skin wounds measured the rate at which new cells closed a razor cut made in the skin of an anesthetized newt. Here are data from 18 newts, measured in micrometers per hour: 29,27,34,40,22,28,14,35,26,35,12,30,23,18,11,22,23,33. Questions: a)...
*April 25, 2007 by Natasha*

**Statistics**

I have a problem I need some help on. I answered some. For many years the numbers of accidents per week at a hazardous intersection have been studied. The number of accidents per week varies with mean 2.2 and standard deveiation 1.4. 1. Could the exact distributin of the ...
*August 4, 2007 by Kayse*

**math**

One week Trey rented 4 DVDs and 2 video games for $18. The next week he rented 2 DVDs and 1 video game for $9. Find the rental costs for each video game and DVD.
*January 22, 2014 by anne*

**statistics**

A student union wants to obtain a 90% confidence interval for the proportion of “full time” students who hold a part-time job for 20 hours or more per week. For this purpose, they want to interview a sample of full-time students. They want a margin of error to be at most 0.1, ...
*December 20, 2013 by Steven *

**Statistics**

A random sample of 50 students chosen from an elementary school with 400 students was found to have a mean allowance of $26 per week with a standard deviation of $8. Obtain a 98% confidence interval for the total amount of allowance money given to students in this school per ...
*November 13, 2013 by Cam*

**Math**

Please help me.. There is question : calculate the number of hours of learning sessions in a week, and then specify the amount of hours of mathematics lessons out of the entire hours of learning sessions in a week expressed in a fraction! I Dont know.. what the mean it ? :P ...
*August 9, 2011 by Putra*

**MATH Statistics**

A student union wants to obtain a 90% confidence interval for the proportion of “full time” students who hold a part-time job for 20 hours or more per week. For this purpose, they want to interview a sample of full-time students. They want a margin of error to be at most 0.1, ...
*December 20, 2013 by Steven *

**math function rule input/output**

during a 10 hr train trip the distance you travel equals 45 miles per hour the number t of hours spent traveling The distance travelled is speed x time. Your question seems to be stated incorrectly. You say the travel time in the begining of the sentence and then ask for what ...
*March 21, 2007 by Anonymous*

**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 ...
*June 18, 2012 by Mike*

**statistics**

A random sample of 16 mid-sized cars tested for fuel consumption gave a mean of 26.4 kilometers per liter with a standard deviation of 2.3 kilometers per liter. i) Assuming that the kilometers per liter given by all mid-sized cars have a normal distribution, find a 99% ...
*May 10, 2012 by Koia*

**Statistics**

28. A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spend studying per week. Based on a simple random sample, they surveyed 144 students. The statistics showed that students studied an average of...
*October 22, 2011 by Steph*

**math**

find the minimum, maximum,range,median,mean,mode for the hours of television watched per week 1 to 8 student and 10 to 30 hours per week?
*October 28, 2010 by Anonymous*

**Basic Statistics**

A random sample of 16 mid-sized cars tested for fuel consumption gave a mean of 26.4 kilometers per litre with a standard deviation of 2.3 kilometers per litre. (a)Assuming that the kilometers per litre given by all mid-sized cars have a normal distribution,find a 99% ...
*October 15, 2014 by John*

**MATH**

Could someone please double check me? ------------------------------------------ A Developer works 40 hours per week at $30 per hour. He or she earns : 40 hours x $30.00 per hour = $1200.00 - per week. The four developers earn : 40 hours x $1200.00 = $4800.00 - per week...
*November 23, 2009 by Rachel*

**statistics**

A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 15 hours, with a standard deviation of 3.5 hours. It is desired to estimate the mean viewing time within one-quarter ...
*October 30, 2011 by Nathalia*

**math**

A small firm produces AM and AM/FM car radios. The AM radios take 15 hours to produce, and the AM/FM radios take 20 hours. The number of production hours is limited to 300 hours per week. The plant’s capacity is limited to a total of 18 radios per week, and existing orders ...
*January 22, 2008 by amy*

**Confidence Intervals**

Over the last 15 Major League Baseball seasons, the mean number of strikeouts by the American League leader is 258.5. Assuming that the number of strikeouts by the league leader is normally distributed and the standard deviation for all seasons in all leagues is 34.9, find the...
*June 20, 2008 by melanie*

**Statistics**

The standard deviation for a population is σ = 15.3. A sample of 36 observations selected from this population gave a mean equal to 74.8. a) Make a 90% confidence interval for μ b) Construct a 95% confidence interval for μ. c) Determine a 99% confidence interval...
*November 21, 2013 by ----*

**statistics**

A random sample of 16 mid-sized cars tested for fuel consumption gave a mean of 26.4 kilometers per liter with a standard deviation of 2.3. (a) Assuming that the kilometers per liter given by all mid-sized cars have a normal distribution, find a 99% confidence interval for the...
*October 25, 2014 by Angee*

**Math Statistics**

5. Students in an introductory statistics class were asked to report the age of their mothers when they were born. Summary statistics include Sample size: 36 students Sample mean: 29.643 years Sample standard deviation: 4.564 years a. Calculate the standard error of this ...
*July 29, 2013 by James*

**Statistics**

Professor York randomly surveyed 240 students at Oxnard University, and found that 150 of the students surveyed watch more than 10 hours of television weekly. Develop a 95% confidence interval to estimate the true proportion of students who watch more than 10 hours of ...
*April 7, 2014 by Angela*

**Statistics**

This is my first stats class and I don't know how to do this, could you please help me? Thank you. You are asked to determine the typical number of sales of a certain product at the store you work for. A sample of 50 days over the last quarter shows an average of 55 units sold...
*October 31, 2011 by Melvin*

**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 ...
*April 27, 2013 by Steph*

**Statistics**

1. This probability distribution shown below relates to the number of times a person goes to a local coffee shop per day. What is the expected mean (average) number of times a person goes to a local coffee shop per day? 2. What is the area equal to under a normal curve ...
*May 23, 2014 by Jake*

**Statistics**

A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 12 hours, with a standard deviation of 3 hours. It is desired to estimate the mean viewing time within one quarter ...
*December 2, 2010 by Shyra*

**statistics**

In a time-use study, 20 randomly selected managers were found to spend a mean of 2.40 hours each day on paperwork. The standard deviation of the the 20 scores is 1.30. Also, the sample data appear to have a bell-shaped distribution. Construct the 95% confidence interval for ...
*July 30, 2012 by vickie*

**statistics**

In a time-use study, 20 randomly selected managers were found to spend a mean of 2.40 hours each day on paperwork. The standard deviation of the the 20 scores is 1.30. Also, the sample data appear to have a bell-shaped distribution. Construct the 95% confidence interval for ...
*July 30, 2012 by jamie*

**stats**

4. Data from the 2008 General Social Survey (GSS) sample show that the mean number of children per respondent was 1.94 with a standard deviation of 1.70. A total of 2,020 people answered this question. (a) Estimate the population mean number of children per adult using a 90% ...
*July 26, 2012 by taylor quenzler*

**stats**

In a transportation study of 20 large cities, it was found that the mean of the number of cars per person was 0.504. (Some of the people in the city are children.) The study also stated that the standard deviation s was 0.123. Find a 95 % confidence interval for the true mean ...
*March 31, 2013 by chris*

**stats**

n a transportation study of 20 large cities, it was found that the mean of the number of cars per person was 0.504. (Some of the people in the city are children.) The study also stated that the standard deviation s was 0.123. Find a 95 % confidence interval for the true mean ...
*March 31, 2013 by chris*

**Math**

Carlos sells video games on a web site. the cost for his web site is $75 per year. Carlos sells each video game for $25. Which equation can Carlos use to determine how many video games "g", he must sell to make a profit of $50 per year? A. 100g = 50 B. 75g + 25 = 50 C. 25g + ...
*December 16, 2012 by Candi*

**Math**

A company is considering offering child care for their employees. They wish to estimate the mean weekly child-care cost of their employees. A sample of 10 employees reveals the following amounts spent last week in dollars. 107 92 97 95 105 101 91 99 95 104 Develop a 90% ...
*October 30, 2011 by Monica*

**Math**

What price do farmers get for the peach crops? in the third week of June, a random sample of 40 farming regions gave a sample mean of $6.88 per basket. assume that the standard deviation is known to be $1.92 per basket. find a 90% confidence interval for the population mean ...
*August 7, 2011 by Justina*

**Statistics**

Problem 6 A histogram shows the number of hours students spent preparing for a test. The table below gives the intervals and the heights of the bars (in percent per hour). Intervals contain the left endpoint but not the right. No student spent 25 hours or more in preparation. ...
*February 25, 2013 by A*

**Statistics**

1. A certain population follows a normal distribution, with mean m and standard deviation s = 2.5. You collect data and test the hypotheses H0: m = 1, Ha: m 1. You obtain a P-value of 0.022. Which of the following is true? Why? a. A 95% confidence interval for m will include ...
*November 29, 2008 by Latoya*

**English**

I was wondering what you all may think about video games and their effects on children playing them? Are the children becoming more violent? What do these games do t a child's psyche?
*November 9, 2011 by Benjamin*

**Algebra 2**

Amanda surveyed 20 juniors and seniors at Delamar high school to find the number of hours per week they spend working at part-time jobs. Her results are shown below. Juniors: 20,10,20,10,15,0,0,10,20,15 Seniors: 20,20,10,10,0,0,0,10,0,10 which statement about the data is true...
*May 19, 2014 by Danny*

**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...
*May 3, 2013 by Cam*

**statistics**

What do confidence intervals represent? What is the most controllable method of increasing the precision of or narrowing the confidence interval? What percentage of times will the mean, or population proportion, not be found within the confidence interval?
*April 30, 2010 by Amy*

**Statistics**

If someone gives you a sample mean and a standard deviation, you can find a confidence interval. But what if someone gives you the confidence interval instead and asks you to find the sample mean? How can you do that? Here's an example: a 95% confidence interval for a mean is ...
*October 4, 2011 by Hope*

**Statistics**

Which of the following statements correctly interprets a 95% confidence interval on a population mean? a. It is a single point estimate b. Used to quantify the certainty of the sample standard deviation c. A 99% confidence interval is narrower than the 95% confidence interval ...
*September 15, 2010 by Beata Chmielewska*

**statistics**

The population standard deviation (σ) for a standardized achievement test that is normally distributed is 8. a.) Calculate the standard error of the mean if you draw a random sample of 50 test scores. Show your work for full credit . . . b.) Your sample mean is ...
*February 21, 2012 by PK*

**Calc**

A video games shop is analyzing its sales performance using matrices. Matrix A contains the unit sales data for each product category (horizontally) per week (vertically). Matrix B contains the unit sales data for weekends for each category (horizontally) per week (vertically...
*April 25, 2013 by Chris*

**statistics**

A researcher believe that college students spend a different amount of time talking on the phone than they do instant messaging. She takes a random sample of 12 college students and records the number of hours per week each student spends on each activity and plans to test at ...
*April 26, 2014 by anon*

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