6.35 Change the sample size.

Consider the setting of the previous exercise. Suppose that the sample mean is again 82 and the population standard deviation is 7. Make a diagram similar to Figure 6.10 (page 309) that illustrates the effect of sample size on the width of a 95% interval. Use the following sample sizes: 10, 20, 40, and 80. Summarize what the diagram shows.