Question 8.7

7. Assume that the confidence level increases.

  1. What happens to the value of ? (p. 432)
  2. Explain why this happens. Draw a sketch to help you. (p. 432)

8.1.7

(a) increases. (b) Since the confidence level is , as the confidence level increases, increases. Thus and will decrease. Since is the area underneath the standard normal curve to the right of , a decrease in will result in an increase in .