6.36 Change the confidence.

Consider the setting of the previous two exercises. Suppose that the sample mean is still 82, the sample size is 30, and the population standard deviation is 7. Make a diagram similar to Figure 6.11 (page 310) that illustrates the effect of the confidence level on the width of the interval. Use 80%, 90%, 95%, and 99%. Summarize what the diagram shows.