10.27) In contract negotiations, a company claims that a new incentive scheme has resulted in average weekly earnings of at least $400 for all customer service workers. A union representative takes a random sample of 15 workers and finds that their weekly earnings have an average of $381.35 and a standard deviation of $48.60. Assume a normal distribution. ("Statistics for Business and Economics, Sixth Edition" by Paul Newbold et al.)
a. Test the company's claim.
H0: the mean is greater than or equal to 400
H1: the mean is less than 400
Okay...so I calculated that t = -1.486, but I don't know where to go from there. From running the T-test program on my calculator I found that the p-value is 0.797, meaning I would reject H0 at alpha levels greater than 7.97%. My question is, how do I solve for this p-value without a calculator program (just using the charts), since I won't be allowed to use calculator programs and statistical tests on my test? THANK YOU!