A sample of a given size is used to construct a 95% confidence interval for the population mean with a known population standard deviation.If a bigger sample had been used instead,then the 95% confidence interval would have been _______ and the probability of making an error would have been ________.
A)Wider,smaller
B)Narrower,smaller
C)Wider,unchanged
D)Narrower,unchanged

Question

Quizplus · Accepted Answer

The larger sample size would lead to a smaller standard error of the mean, which in turn would lead to a narrower confidence interval. The confidence level and population standard deviation remain the same, so the probability of making an error would be unchanged. Therefore, option D is correct.

A Sample of a Given Size Is Used to Construct