1/21/24, 10:59 AM Aplia: Student Question Back to Assignment Attempts | 0 | | | Keep the Highest 0 / 3 10. Gravetter/Wallnau/Forzano, Essentials - Chapter 10 - End-of-chapter question 21 For each of the following, assume that the two samples are obtained from populations with the same mean, and calculate how much difference should be expected, on average, between the two sample means. Each sample has n = 7 scores with s2 = 142 for the first sample and s2 = 110 for the second. (Note: Because the two samples are the same size, the pooled variance is equal to the average of the two sample variances.) 6.00 Points: 0/1 Explanation: Close Explanation The pooled variance is s3 = (s? + s3) / 2 = (142 + 110) / 2 = 252/2 = 126. The estimated standard error for the sample mean difference is sp1 - M2 = V(s3/nl + s3/n2) = V36 = 6 points. Each sample has n = 28 scores with s2 = 142 for the first sample and s2 = 110 for the second. 3.00 Points: 0/1 Explanation: Close Explanation The pooled variance is s3 = (s? + s2) / 2 = (142 + 110) / 2 = 252/2 = 126. The estimated standard error for the sample mean difference is sy1-M2 = \/(s%/nl + s%/nZ) = V9 = 3 points. In the second part of this question, the two samples are bigger than in the first part, but the variances are unchanged. How does the sample size affect the size of the standard error for the sample mean difference? X O As sample size increases, standard error increases. v @ As sample size increases, standard error decreases. O As sample size increases, standard error remains the same. Points: 0/1 Explanation: Close Explanation Larger samples produce a smaller standard error. Try Another Version Continue https://ng.cengage.com/static/nb/ui/evo/index.html?deploymentld=5993921885004398785893731831&elSBN=9780357035542&id=1958964838&sna... 1/1
