In the formula for finding a confidence interval when the value of the population standard deviation is unknown,we change N to N - 1.The reason for this change is
A)to correct for the fact that s is biased.
B)the standard deviation of a sample is always greater than the standard deviation of the population.
C)the standard deviation of a sample is unbiased.
D)sample size is much too large.

Question

Quizplus · Accepted Answer

When the population standard deviation is unknown, the sample standard deviation (s) is used as an estimate. However, s is a biased estimate of the population standard deviation. To correct for this bias, we use the formula with N-1 instead of N, which is called Bessel's correction. This adjustment makes the sample standard deviation an unbiased estimator of the population standard deviation. Therefore, Choice A is the correct answer.

In the Formula for Finding a Confidence Interval When the Value