The daily revenue from the sale of fried dough at a local street vendor in Boston is known to be normally distributed with a known standard deviation of $120.The revenue on each of the last 25 days is noted,and the average is computed as $550.A 95% confidence interval is constructed for the population mean revenue.If the data from the last 40 days had been used,then the resulting 95% confidence intervals would have been _____________________.
A)Wider,with a larger probability of reporting an incorrect interval
B)Wider,with the same probability of reporting an incorrect interval
C)Narrower,with a larger probability of reporting an incorrect interval
D)Narrower,with the same probability of reporting an incorrect interval

Question

Quizplus · Accepted Answer

Using data from more days (40 instead of 25) would result in a narrower confidence interval because the standard error decreases with a larger sample size. The probability of reporting an incorrect interval remains the same at 5% for a 95% confidence interval.

The Daily Revenue from the Sale of Fried Dough at a Local