Assuming the sample mean and standard deviation are the same for different combinations of levels of confidence and sample size, as the sample size ______, the level of confidence has ______ impact on the width of the confidence interval.
A) decreases; the same
B) decreases; less
C) increases; more
D) increases; less

Question

Quizplus · Accepted Answer

As the sample size increases, the impact of the level of confidence on the width of the confidence interval decreases because the standard error (which is part of the calculation for the confidence interval and depends on the sample size) becomes smaller, making changes in the z* or t* multiplier (which adjust for confidence level) less impactful on the overall width of the confidence interval.

Assuming the Sample Mean and Standard Deviation Are the Same