In 2010, an online security firm estimated that 64% of computer users don't change their passwords very often. Because this estimate may be outdated, suppose that you want to carry out a new survey to estimate the proportion of students at your school who do not change their password. You would like to determine the sample size required to estimate this proportion to within a margin of error of 0.04 with 95% confidence. (a) Using 0.64 as a preliminary estimate, what is the required sample size if you want to estimate this proportion with a margin of error of 0.04? (Round your answer up to the nearest whole number.) Calculate the required sample size using the conservative value of 0.5. (Round your answer up to the nearest whole number.) How do the two sample sizes compare? The sample size calculated using 0.64 is --Select--- - the sample size calculated using the conservative estimate. (b) What sample size would you recommend? Justify your answer. The --Select-- v should be used for this study because it will guarantee a margin of error of no greater than 0.04. The other sample size calculated will only guarantee a margin of error no greater than 0.04 if p > or if p <

In 2010, an online security firm estimated that 64% of computer users don't change their passwords very often. Because this estimate may be outdated, suppose that you want to carry out a new survey to estimate the proportion of students at your school who do not change their password. You would like to determine the sample size required to estimate this proportion to within a margin of error of 0.04 with 95% confidence. (a) Using 0.64 as a preliminary estimate, what is the required sample size if you want to estimate this proportion with a margin of error of 0.04? (Round your answer up to the nearest whole number.) Calculate the required sample size using the conservative value of 0.5. (Round your answer up to the nearest whole number.) How do the two sample sizes compare? The sample size calculated using 0.64 is --Select--- - the sample size calculated using the conservative estimate. (b) What sample size would you recommend? Justify your answer. The --Select-- v should be used for this study because it will guarantee a margin of error of no greater than 0.04. The other sample size calculated will only guarantee a margin of error no greater than 0.04 if p > or if p <

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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A physical therapist wants to determine the difference in the proportion of men and women who participate in regular sustained physical activity. What sample size should be obtained if she wishes the estimate to be within five percentage points with 95% confidence, assuming that (a) she uses the estimates of 22.9% male and 19.5% female from a previous year? (b) she does not use any prior estimates?
In 2010, an online security firm estimated that 61% of computer users don't change their passwords very often. Because this estimate may be outdated, suppose that you want to carry out a new survey to estimate the proportion of students at your school who do not change their password. You would like to determine the sample size required to estimate this proportion to within a margin of error of 0.05 with 95% confidence. Using 0.61 as a preliminary estimate, what is the required sample size if you want to estimate this proportion with a margin of error of 0.05? (Round your answer up to the nearest whole number.) Calculate the required sample size using the conservative value of 0.5. (Round your answer up to the nearest whole number.) What sample size would you recommend? Justify your answer.
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A physical therapist wants to determine the difference in the proportion of men and women who participate in regular sustained physical activity. What sample size should be obtained if she wishes the estimate to be within three percentage points with 90% confidence, assuming that (a) she uses the estimates of 21.7% male and 18.7% female from (b) she does not use any prior estimates? previous year? (a) n= (Round up to the nearest whole number.) (b) n= (Round up to the nearest whole number.)
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