The average weekly earnings of aproduction worker in 2000 were AUD428428. Suppose a labor researcher wants to test todetermine whether this figure is still accurate today.

The researcher randomly selects6060production workers and obtains a representativeearnings statement for one week from each. The resulting sample average is AUD433.1433.1.

Assuming a population standard deviation of AUD32.032.0, and a 5% level of significance,determine whether the mean weekly earnings of a production worker have changed.

Determine the critical value zc and z score value z based on the sample data.

The critical value zc==

The z score value z based on the sample data =

Question 2

A random sample of n=n= 1616items is taken, resulting in a sample meanofx=16.5with a sample standard deviationof s=4.2.

Assume x is normally distributed and use this information and 0.05 test the following hypotheses.

H0H0: =16

HaHa: 16

Determine the critical value tc and t score value tt based on the sample data.

The critical value tc=

The t score value t based on the sample data =

Question 3

A community health association is interested in estimating the average number ofmaternity days women stay in the local hospital.A random sample is taken of16 women who had babies in the hospital during the past year. The followingnumbers of maternity days each woman was in the hospital are rounded to thenearest day.

5 2 6 2 6 1 3 1 3 2 1 1 7 1 3 6

Use these data and a population standard deviation of 1.21.2to construct a9898%confidence interval to estimate the average maternity stay in the hospital for allwomen who have babies in this hospital.

Lower Confidence Limit (L.C.L) ==

Upper Confidence Limit (U.C.L) =