Chapter 18, Problem 8E

Home sales again In the previous exercise, you found a 95% confidence interval to estimate the average loss in home value.

1. a) Suppose the standard deviation of the losses had been $3000 instead of $1500. What would the larger standard deviation do to the width of the confidence interval (assuming the same level of confidence)?
2. b) Your classmate suggests that the margin of error in the interval could be reduced if the confidence level were changed to 90% instead of 95%. Do you agree with this statement? Why or why not?
3. c) Instead of changing the level of confidence, would it be more statistically appropriate to draw a bigger sample?