Friday

September 30, 2016
Number of results: 91,367

**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*

**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*

**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**

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*

**Stastics**

Which of the following descriptions of confidence intervals is correct? (Select all that apply) a. If a 95% confidence interval contains 0, then the 99% confidence interval contains 0 b. If a 99% confidence interval contains 0, then the 95% confidence interval contains 0 c. If...

*April 25, 2016 by Lindsay*

**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*

**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**

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**

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. 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*

**INTERVAL OF THE MEAN**

In a test of of garlic for lowering cholesterol, 45 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured beforeandafter the treatment. The changes in their levels of LDL cholesterol (in mg/dL) have a mean of 5.4 and a sd of 17.5. ...

*May 26, 2015 by Lynn*

**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**

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**

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**

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**

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*

**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**

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 **

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 *

**probs & stats**

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 11, 2015 by adrenning*

**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*

**Statistics**

. As the sample size increases The confidence interval also increases (gets larger) The confidence interval decreases (gets smaller) The confidence interval stays the same The population mean increases.

*June 22, 2010 by Jacob*

**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**

What is meant by the 95% confidence interval of the mean ? That 95% of my sample is OK to do more tests. That I am 95% confident that the confidence interval will contain the parameter being estimated. That 5% of my sample is not OK. That I am 95% sure that the population mean...

*June 22, 2010 by Jacob*

**statistics**

What is meant by the 95% confidence interval of the mean ? That 95% of my sample is OK to do more tests. That I am 95% confident that the confidence interval will contain the parameter being estimated. That 5% of my sample is not OK. That I am 95% sure that the population mean...

*August 17, 2010 by Karen*

**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**

A 90% confidence interval for a population mean based on 144 observations is computed to be (2.7,3.4). How many observations must be made so that 90% confidence interval will specify the mean to within ± 0.2

*October 6, 2011 by Prakash*

**statistics**

In a sample of 100 steel wires the average breaking strength is 50 kN, with a standard deviation of 2 kN. a. Find a 95% confidence interval for the mean breaking strength of this type of wire. b. An engineer claims that the mean breaking strength is between 49.7 kN and 50.3 ...

*October 29, 2011 by Don't get it!! :(*

**statistics**

A simple random sample of students is selected, and the students are asked how much time they spent preparing for a test. The times (in hours) are as follows: 1.3 7.2 4.2 12.5 6.6 2.5 5.5 Based on these results, a confidence interval for the population mean is found to be µ = ...

*November 30, 2014 by Brian*

**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 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 *

**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**

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...

*April 26, 2016 by Kapaki Katea*

**statistics**

Can someone guide me on how to solve this problem: A sample of 52 night students ages is obtained in order to estimate the mean age of night school students. sample mean = 25.9 years. the population variance is 23. Give a point estimate for the mean. Find the 95% confidence ...

*January 21, 2012 by concy*

**UOP**

5) In a 95% Confidence Interval, the true mean has what chance of falling between the Lower Limit and Upper Limits of the calculated confidence interval? A. .90 B. 95% C. .05 D. 5%

*April 13, 2013 by Linda*

**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*

**statistics**

Pleas HeLp!!!!!!!!!! A random sample of the test scores of 100 applicants for college entry at a large junior college showed a mean score of 72.6. Determine a 99%, 95%, and 90% confidence interval for the m mean score of all applicants at the junior college. Assume the ...

*September 17, 2011 by courntey*

**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**

A researcher performs a hypothesis test to test the claim that among girls aged 9-10, the mean score on a particular aptitude test differs from 72, which is the mean score for boys of the same age. Data were collected from a random sample of 43 girls aged 9-10 years and the 95...

*November 8, 2013 by Katie*

**Statistics**

Which of the following statements best describes the uncertainty associated with a 95% confidence interval for a population proportion, computed from a simple random sample? A. We don't know whether the particular confidence interval is successful or not, but 95% of ...

*May 18, 2012 by Mary*

**statistics**

Refer to Table 1 in the article “Snail Shells in a Practical Application of Statistical Procedures” in the Electronic Reserve Readings. Find the margin of error, E, with a confidence interval of your choosing (50-99%). What is the significance of choosing a confidence interval...

*April 26, 2012 by len*

**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*

**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*

**statistics**

Consider a 95% confidence interval for a population mean constructed from a random sample of 250 observations taken from a Normal population. Sigma is known to be 14. If we were to construct another 95% confidence interval, this time using 1,000 observations, how would the ...

*February 20, 2011 by AMY*

**statistics**

Consider a 95% confidence interval for a population mean constructed from a random sample of 250 observations taken from a Normal population. Sigma is known to be 14. If we were to construct another 95% confidence interval, this time using 1,000 observations, how would the ...

*February 20, 2011 by AMY*

**Statistics**

These are the only ones that I am having problems with. Please help.. 8.You are given the sample mean and the sample standard deviation. Use this information to construct the 90% and the 95% confidence intervals for the population mean. Interpret the results and compare the ...

*February 17, 2013 by Katie*

**Environmental Management**

A. The 95% confidence interval is: (a) Larger than the 99% confidence interval (b) Smaller than the 99% confidence interval (c) The same as the 99% confidence interval

*July 13, 2009 by Jox*

**statistics**

A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is 15. a) Compute the 95 % confidence interval for the population mean. b) Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence ...

*April 7, 2011 by TIMBERLY*

**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 HELP!**

A data set includes body temperatures of healthy adult humans for which 98.1F and s= 0.56F. What is the best point estimate of the mean body temperature of all healthy humans? Using the sample statistics, construct a confidence interval estimate of the mean body temperature of...

*December 16, 2014 by Jenny*

**statistics**

A data set includes body temperatures of healthy adult humans for which x= 98.2 and s=0.64 F. Complete parts a) and b) below a) what is the best point estimate of the mean body temperature of all healthy humans? The best point estimate is F. b) Using the sample statistics, ...

*November 19, 2013 by anonymous*

**statistics**

The Frayed Nerves Anxiety Scale (FNAS) is used to measure the anxiety level of people on a scale from 0 to 1000. Four students were randomly chosen and given the FNAS before their second exam. Their scores were 700, 653, 740, and 707. The standard deviation sigma of the test ...

*October 17, 2011 by Anand*

**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**

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**

Please help!! I have no idea how to do this question. 14. A sample of 40 CD’s from your collection showed a mean length of 52.74 minutes with a standard deviation of 13.21 minutes a. Construct the 95 percent confidence interval for the mean. b. Construct the 95 percent ...

*October 31, 2011 by Kristi*

**Math-Stat Help **

In a random sample of 78 teenagers, 32 admit to texting while driving. Construct a 98% confidence interval for the percentage of teenager that text while driving. Start by showing that conditions for constructing a confidence interval are met. 1) Check conditions 2) confidence...

*April 11, 2013 by MELISSA *

**Statistics**

In 1998 a San Diego Reproductive clinic reported 49 live births to 207 women under the age of 40 who had previously been unable to get pregnant. Using the 90% confidence interval calculated above, would it be misleading for the clinic to report a success rate of 25%? A) Yes, ...

*October 27, 2013 by Jeffrey*

**statistics**

Randomly selected students participated in an experiment to test their ability to determine when one minute(or sixty seconds) has passed. Forty students yielded a sample mean of 61.8 seconds. Assuming that o= 11.7 seconds, Construct and interpret a 99% confidence interval ...

*November 17, 2013 by anonymous*

**Statistics**

A simple random sample of 50 female 14-year-olds is selected. The sample mean height of the girls is found to be 62 inches. Assume the height of 14-year-old girls is normally distributed with a standard deviation of 5 inches. 1. Based on these data, a 95% confidence interval ...

*November 27, 2012 by Clay*

**Descriptive Statistics**

. 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 ...

*March 25, 2009 by Karen*

**BIOLOGY - LAB**

What is Confidence Interval? Is it better to have a large Confidence Interval or a small Confidence Interval? Briefly explain.

*March 24, 2009 by biology*

**statistics**

Help!!!!!! A confidence interval estimate for the population mean is given to be (39,90, 48.11) If the standard deviation is 11.473 and the sample size is 52 determine the maximum error of the estimate. determine the confidence level used for the given confidence interval

*November 9, 2011 by amy*

**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**

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*

**Statistics (42)**

A simple random sample of 60 items resulted in a sample mean of 96. The population standard deviation is 16. a. Compute the 95% confidence interval for the population mean (to 1 decimal). ( , ) b. Assume that the same sample mean was obtained from a sample of 120 items. ...

*May 6, 2014 by Mia*

**Statistics**

The 95% confidence interval is: (a) Larger than the 99% confidence interval (b) Smaller than the 99% confidence interval (c) The same as the 99% confidence interval

*October 28, 2007 by Thano*

**MATH (STATS)**

To determine the views of a students on a particular campus about fraternities, an 11-point attitude scale was administered to a random sample of 40 students. This survey yielded a sample mean of 6 (the higher the score, the more favorable the view of the fraternities) and a ...

*October 8, 2014 by Taylor*

**statistics**

A sample of n = 9 has a mean of M = 72 with SS = 162. Use the sample to make a point estimate of ě and to construct the 90% confidence interval for ě. (Round all answers to two decimal places ě = ? ± ? ( ? ) The 90% confidence interval for ě: ( ? , ? )

*November 4, 2011 by Anonymous*

**statistics**

A sample of n = 9 has a mean of M = 72 with SS = 162. Use the sample to make a point estimate of ě and to construct the 90% confidence interval for U. (Round all answers to two decimal places.) U = ? ± ? ( ?) The 90% confidence interval for U: ( ? , ? )

*November 4, 2011 by Anonymous*

**stat**

7. A researcher selects a random sample. A 90% confidence interval for a population mean A) is an interval with margin of error ± 90%. B) has the property that if we repeatedly selected our random sample in exactly the same way, each time constructing a different 90% ...

*December 5, 2010 by Anonymous*

**Statistics**

Multiple Choice Which of the following statements is true about the 95% confidence interval of the average of a sample? A) 95 of 100 avgs of samples will be within the limits of the confidence interval. B) There is a 95% chance the avg of the population to be within the limits...

*July 26, 2013 by Andrew*

**statistics**

How large a sample would be needed to form a 90% confidence interval for the mean nicotine content of a brand of cigarettes if the nicotine content has a normal distribution with sigma equal to 8.5 mg and the width of the interval (the length of the confidence interval) equal ...

*November 17, 2013 by Alex*

**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**

We have calculated a 95% confidence interval for a proportion and would prefer the confidence interval to be more precise, that is narrower. Using the same sample, we can narrow the confidence interval using which of the following? A) increasing the confidence level B) ...

*October 27, 2013 by Nick*

**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*

**Math**

Suppose a population is sampled and the sample mean is 16.8. The sample standard deviation is 6.0 I am to assume the sample is larger than 30) and the sample size is 65. How do I calculate 95% and 98% confidence intervals. State which interval wider and why please. How would I...

*February 13, 2013 by Mandi*

**statistics**

A basketball scout randomly selected 144 players and timed how long each player took to perform a certain drill. The times in this sample were distributed with a mean of 8 minutes. The population standard deviation was known to be 3 minutes. A. find the critical value for a 95...

*April 27, 2014 by Mark*

**Math **

Calcium is essential to tree growth because it promotes the formation of wood and maintains cell walls. In 1990, the concentration of calcium in precipitation in a certain area was 0.11 milligrams per liter (mg/L). A random sample of 10 precipitation dates in 2007 results in ...

*December 3, 2014 by LADO*

**statistics**

A sample of 134 golfers showed that their average score on a particular golf course was 87.43 with a standard deviation of 4.53. Answer each of the following (show all work and state the final answer to at least two decimal places.): (A) Find the 99% confidence interval of the...

*November 2, 2010 by Valerie*

**statistics**

A sample of 106 golfers showed that their average score on a particular golf course was 87.98 with a standard deviation of 5.39. Answer each of the following (show all work and state the final answer to at least two decimal places.): (A) Find the 90% confidence interval of the...

*September 2, 2011 by Laynette*

**statistics**

twelve different vTideo 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 sample data to construct a 95...

*June 15, 2015 by melissa jones*

**Statistics**

In a study to estimate a population mean, i start with a sample size 10 and calculate the 95% confidence interval. Suppose i am not satisfied with the size of the confidence interval and want to reduce it by half. Give an estimate of sample size that i need.

*August 23, 2010 by Zodra*

**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**

Bacterial samples were taken from several surfaces in a daycare and incubated in petri dishes. After that the number of bateria colonies were counted, with the following results 412, 437, 425, 476, 451, 483. 1) construct a 95% confidence interval for the mean number of ...

*October 11, 2007 by Keirson*

**Statistics 101**

A researcher plans to use a random sample of n= 500 families to estimate teh mean monthly family incomefor a large population. a 99% confidence interval based on the sample would be _________ than 90% confidence interval.

*February 25, 2014 by Deedy*

**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 *

**mba business reserach methods**

Sampling A manufacturing company's quality control personnel have recorded the proportion of defective items for each of 500 monthly shipments of one of the computer components that the company produces. See data below. The company doesn't have time to review all of these. (a...

*March 20, 2011 by Carolina*

**MATH **

The following data represent the asking price of a simple random sample of homes for sale. Construct a 99% confidence interval with and without the outlier included. Comment on the effect the outlier has on the confidence interval. Here is the information: $231,500 $279,900 $...

*November 30, 2014 by LADO*

**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*

**statistics**

Ok, so I'm trying to do this for my exam review. I get some of it, but not all: An electric utility is examining the relationship between temperature and electricity use in its service region on warm days. The utility has bivariate data detailing the maximum temperature (...

*May 15, 2010 by peter*

**Math Stats**

The following data represent the asking price of a simple random sample of homes for sale. Construct a 99% confidence interval with and without the outlier included. Comment on the effect the outlier has on the confidence interval. Here is the information: $231,500 $279,900 $...

*November 30, 2014 by STATS 3*

**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**

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*

**math 3**

The following data represent the asking price of a simple random sample of homes for sale. Construct a 99% confidence interval with and without the outlier included. Comment on the effect the outlier has on the confidence interval. Here is the information: $231,500 $279,900 $...

*December 4, 2014 by LADO*

**Statistics**

Express the confidence interval using the indicated format. Express the confidence interval -0.129 < p < 0.631 in the form of p ± E.

*July 21, 2014 by tray*

**statistic**

For a given month, a random sample of 30 sales girls from a superstore has a sample mean of salary of RM 800 with standard deviations of RM 140. Estimate the mean monthly salary for all employees using the 95% confidence interval.(what does mean of 95% confidence level?)

*September 27, 2011 by niki*