b) A company attempts to evaluate the potential for a new bonus plan by selecting a random sample of five salespersons to use the bonus plan for a trial period. Weekly sales volumes before and after...

Extracted text: b) A company attempts to evaluate the potential for a new bonus plan by selecting a random sample of five salespersons to use the bonus plan for a trial period. Weekly sales volumes before and after implementing the bonus plan are shown below. Salesperson 4 Before 12 11 19 15 18 After 15 13 18 18 20 Test at a 10% significance level, to see if the bonus plan will result in an increase in the mean weekly sales.