An auto manufacturer wants to estimate the annual income of owners of a particular model of automobile. A random sample of 200 current owners is selected. The population standard deviation is known. Which Excel function would NOT be appropriate to use to construct a confidence interval estimate?

Question

Quizplus · Accepted Answer

COUNTIF is used to count the number of cells that meet a certain criteria. It is not relevant for constructing a confidence interval estimate of the population income. However, NORM.S.INV, AVERAGE and STDEV are appropriate functions to use in constructing a confidence interval. NORM.S.INV is used to find the z-score for a given confidence level, AVERAGE is used to find the sample mean, and STDEV is used to find the sample standard deviation.

An Auto Manufacturer Wants to Estimate the Annual Income of Owners