Population Mean: Unknown

In the past, the average age of employees of a mid-sized corporation has been 35 years. Recently, the company has been hiring older individuals. In order to determine whether there has been an increase in the average age of all the employees, a sample of 64 employees was selected. The average age in the sample was 45 years with a standard deviation of 16 years. Let = .05.

13.

State the null and the alternative hypotheses.

14.

Compute the test statistic.

15.

Using the p-value approach, test to determine whether or not the mean age of all employees is significantly more than 40 years.

Population Proportion

Consider the following hypothesis test:

H₀: p .8

H_a: p > .8

A sample of 500 provided a sample proportion of .853.

16.

Determine the standard error of the proportion.

17.

Compute the value of the test statistic.

18.

Determine the p-value; and at a 5% level, test the above hypotheses.