1. The starting annual salaries for students graduating from two departments, X and Y, of a university are being investigated. Two random samples of last year's intake have been selected and the results are as follows: Department Sample size Mean starting monthly salary Standard deviation X 15 $20,000 $5,100 Y 15 130 $18,000 $3,200 Test the hypothesis that graduates from Department X earn more than those from Department Y at two appropriate levels and comment on your results