Here = , , n = 15 ( n < 30, here we use t test confidence interval)
Confidence interval for the population mean =
Degrees of freedom = n-1 = 14
Confidence interval = 90%
Therefore, t = 1.761 ... Using t distribution table
90% confidence interval for population mean
Similarly,
99% confidence interval for population mean
Confidence interval = 99%
Therefore, t = 2.977
99% confidence interval (7.1 , 10.1) is wider than 90% confidence interval (7.7, 9.5).
- publisher wants to estimate the mean length of time in minutes) all adults spend reading...
10 A publisher wants to estimate the mean length of time (in minutes) all adults spend reading newspapers. To determine this estimate the publisher takes a random sample of 15 people and obtains the results below. From past studies, the publisher assumes o is 23 minutes and that the population of times is normally distributed 12 9 10 7 9 8 7 12 12 6 11 9 9 Construct the 90% and 99% confidence intervals for the population mean. Which...
a published wants to estimate the mean length of time all adults spend reading news papers. to determine the estimate the publisher take a random number sample of 15 people and obtained the results below. from past studies, the publisher assumes õ is 1.7 minutes and that the population of times normally distributed. 6, 10,10,11,11,10,6,8,7,7,8,7,8,12,9. construct the 90% and 99% confidence intervals for the population mean,
8 of 10 (8 complete) HW Score: 71.82%, 7.9 of 11 pts 6.1.45-T Assigned Media Question Help A publisher wants to estimate the mean length of time in minutes) all adults spend reading newspapers. To determine this estimate the publisher takes a random sample of 15 people and obtains the results below. From past studies, the publisher assumes is 21 minutes and that the population of times is normally distributed 12 8 10 11 11 8 11 9 9 6...
Matthew wants to estimate the mean length of time (in minutes) all Senior High students spend reading online news articles. To determine this estimate, he took a random sample of 15 people and obtained the following results: 40, 110, 56, 20, 15, 10, 82, 60, 90, 118, 35, 25, 5, 65, 30. The population of times is normally distributed. Construct the 95% confidence interval for the population mean length of reading time. Type the endpoints of the interval separated by...
A computer company wants to estimate the hours per week adults use computers at home. In a random sample of 31 adults, the mean length of time a computer was used at home was 5.3 hours. From past studies the company assumes that σ = 0.9 hours. Construct the 90% confidence interval for the population mean. (Round confidence interval values to two decimal places.)
Mark wants to estimate the mean length of time (in minutes) all Middle School students spend reading online books. To determine this estimate, he took a random sample of 15 people and obtained the following results: 40, 110, 56, 20, 15, 10, 82, 60, 90, 118, 35, 25, 5, 65, 30. The population of times is normally distributed. What is the margin of error at the 95% confidence level if the population standard deviation is 8 minutes? Round off you...
#17 You are given the sample mean and the population standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Which interval is wider? If convenient, use technology to construct the confidence intervals. A random sample of 34 gas grills has a mean price of $648.20 Assume the population standard deviation is $56.70 The 90% confidence interval is (______,______).
You are given the sample mean and the population standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Which interval is wider? If convenient, use technology to construct the confidence intervals. A random sample of 45 gas grills has a mean price of $648.40 Assume the population standard deviation is $56.50 The 90% confidence interval is
You are given the sample mean and the population standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. If convenient, use technology to construct the confidence intervals. A random sample of 60 home theater systems has a mean price of $135.00 . Assume the population standard deviation is $15.90 . A.) the 90% confidence interval is B.) the 95% confidence interval...
In a survey of 2023 adults in a recent year, 710 made a New Year's resolution to eat healthier. Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. The 90% confidence interval for the population proportion p is ( CD. (Round to three decimal places as needed.) The 95% confidence interval for the population proportion p is (0) (Round to three decimal places as needed.) v of adults...