The width of the confidence interval depends on the sample size. The graph below shows a 95% confidence interval. The data are the training times (in days) for 20 employees. The mean training time was 51.5 days and the standard deviation was 6.84 days. Move the slider below the graph to change the number of observations in the sample and observe how the width of the interval changes. 95% Confidence Interval: [46.61, 56.39] 44 46 48 50 54 56 58 60 n = 10 20 40 Created by Gary H. McClelland, Professor Emeritus I University of Colorado Boulder Cengage Learning. All Rights Reserved. 1. Move the slider to a sample size of n = 10. Now move the slider to a sample size of n = 30. For a given confidence level (in this case 95%) what happens to the width of the confidence interval as the sample size increases? a. As sample size increases, the confidence interval becomes narrower b. As sample size increases, the confidence interval becomes wider c. As sample size increases, the confidence interval remains constant -Select- v 2. If you would like to obtain a margin of error that is + 2.31, what sample size would be required? . 25 b. 43 . 36 d. 18 -Select- v 52