The confidence interval estimate of the expected value of y for a given value x,compared to the prediction interval of y for the same given value of x and confidence level,will be:
A)wider.
B)the same.
C)narrower.
D)impossible to know.

Question

Quizplus · Accepted Answer

The confidence interval estimate of the expected value of y for a given x is narrower than the prediction interval for y at the same x and confidence level because the prediction interval also accounts for the variability (error) in individual y values around the regression line, not just the uncertainty in estimating the mean of y.

The Confidence Interval Estimate of the Expected Value of Y