In 1981, the city of New Orleans reported that its hourly employees made an average

wage of better than $4.00/hour. A federal survey of 225 randomly sampled municipal

hourly employees in New Orleans found that the average hourly wages (for those in

the sample) were $3.86/hour with an SD of $1.20/hour.

(a) What is a likely range for the true average hourly wage of all hourly employees in

New Orleans in 1981? Use the z-table, R, or SAS to find 90% and 95% confidence

intervals.

(b) Do you think the city's claim ($4.00/hr) is - Extremely certain; quite possible;

somewhat likely; or totally improbable? Choose one and explain the reason (using

part (a)).