A manager who is conducting a time study now needs an accuracy of ±0.1 minutes,rather than ±0.2 minutes as in the past.Because of this change in accuracy,the new required sample size becomes:
A)one-fourth as large.
B)one-half as large.
C)twice as large.
D)four times as large.
E)one-tenth larger.

Question

Quizplus · Accepted Answer

The required sample size is inversely proportional to the square of the desired accuracy. Therefore, if the desired accuracy is reduced by a factor of 2 (from 0.2 to 0.1), then the sample size must be increased by a factor of 4 (2 squared). Therefore, the new required sample size is four times as large.

A Manager Who Is Conducting a Time Study Now Needs