Zanele has just begun her new job as on the sales force of a very competitive company. In a sample of 16 sales calls it was found that she closed the contract for an average value of R108 with a...

Zanele has just begun her new job as on the sales force of a very competitive company. In a sample of 16 sales calls it was found that she closed the contract for an average value of R108 with a standard deviation of R12. Test at 5% significance that the population mean is at least R100 and against the alternative that it is less than R100. Company policy requires that new members of the sales force must exceed an average of R100 per contract during the trial employment period. Can we conclude that Zanele has met this requirement at the significance level of 95%?