Answer:
Affects the width of a confidence interval, as the margin of error is a function of the sample standard deviation.
Step-by-step explanation:
When we have the standard deviation for the sample, the t-distribution is used to solve the question.
It does not affect the center of the interval, which is a function only of the sample mean.
Width of a confidence interval:
The width of a confidence interval is a function of the margin of error, which is:
In which s is related to the sample standard deviation. Thus, since s and M are directly proportional, a higher standard deviation makes the interval wider, lower standard deviation makes the interval narrower, and thus, the sample standard deviation affects the the width of a confidence interval.