試題詳解

22. Suppose a 99% comfidence interval for H turr urs out to be (100, 200). To make more useful inferences from tbe data, it is desired to reduce the width of the confidence interval. Which of the following will esult in a retuced interval width?
(A) Incrense the sample size.
(B) Increase the confidence level.
(C) Increase the population mean.
(D) Increase the sample mean.
(E) None of the above.