The manager of a company believes that differences in sales performance depend on the salesperson's age. Independent samples of salespeople were taken and their weekly sales is reported below.
Below 30 Years Between 30 and 45 Years Over 45 Years
No. of sales No. of sales No. of sales
24 23 30
16 17 20
21 22 23
15 25 25
19 18 34
26 29 36
27 28
a. State the null and alternative hypotheses.
b. At 95% confidence, test the hypotheses.