In developing an interval estimate for a population mean, the population standard deviation $\sigma$ was assumed to be 10. The interval estimate was 50.92 ± 2.14. Had the population standard deviation$\sigma$ equaled 20, the interval estimate would have been:
A)60.92 ± 2.14.
B)50.92 ± 12.14.
C)101.84 ± 4.28.
D)50.92 ± 4.28.

Question

Quizplus · Accepted Answer

Doubling the population standard deviation from 10 to 20 would double the margin of error in the interval estimate, changing it from ±2.14 to ±4.28, but the center of the interval, 50.92, would remain the same.

In Developing an Interval Estimate for a Population Mean, the Population