A simple random sample of size n is drawn from a population that is known to be normally distributed. The sample variance, s?, is determined to be 12.8. Complete parts (a) througl (c). (a) Construct a 90% confidence interval for o? if the sample size, n, is 20. The lower bound is (Round to two decimal places as needed.) The upper bound is (Round to two decimal places as needed.) (b) Construct a 90% confidence interval for o if the sample size, n, is 30. The lower bound is (Round to two decimal places as needed.) The upper bound is (Round to two decimal places as needed.) How does increasing the sample size affect the width of the interval? The width decreases The width increases The width does not change (c) Construct a 98% confidence interval for o if the sample size, n, is 20. The lower bound is (Round to two decimal places as needed.) The upper bound is (Round to two decimal places as needed.) Compare the results with those obtained in part (a). How does increasing the level of confidence affect the confidence interval? The width increases The width does not change The width decreases

A simple random sample of size n is drawn from a population that is known to be normally distributed. The sample variance, s?, is determined to be 12.8. Complete parts (a) througl (c). (a) Construct a 90% confidence interval for o? if the sample size, n, is 20. The lower bound is (Round to two decimal places as needed.) The upper bound is (Round to two decimal places as needed.) (b) Construct a 90% confidence interval for o if the sample size, n, is 30. The lower bound is (Round to two decimal places as needed.) The upper bound is (Round to two decimal places as needed.) How does increasing the sample size affect the width of the interval? The width decreases The width increases The width does not change (c) Construct a 98% confidence interval for o if the sample size, n, is 20. The lower bound is (Round to two decimal places as needed.) The upper bound is (Round to two decimal places as needed.) Compare the results with those obtained in part (a). How does increasing the level of confidence affect the confidence interval? The width increases The width does not change The width decreases

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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5.STATISTICAL INFERENCE
1.
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This question A simple random sample of size n is drawn. The sample mean, x, is found to be 19.2, and the sample standard deviation, s, is found to be 4.2. Click the icon to view the table of areas under the t-distribution. (a) Construct a 95% confidence interval about u if the sample size, n, is 35. Lower bound:; Upper bound: (Use ascending order. Round to two decimal places as needed.) (b) Construct a 95% confidence interval about u if the sample size, n, is 51. Lower bound: ; Upper bound: (Use ascending order. Round to two decimal places as needed.) How does increasing the sample size affect the margin of error, E? O A. The margin of error does not change. O B. The margin of error decreases. O C. The margin of error increases. (c) Construct a 99% confidence interval about u if the sample size, n, is 35. Lower bound: : Upper bound: (Use ascending order. Round to two decimal places as needed.) Compare the results to those obtained in part (a). How does increasing the level of…
A simple random sample of size n=40 is drawn from a population. The sample mean is found to be x=121.9 and the sample standard deviation is found to be s=12.8. Construct a 99% confidence interval for the population mean. a.) what is the lower bound? b.) what is the upper bound?