we are doing hypothesis testing and i am completely lost please help.

Full time Ph.D. Students receive an average salary of $12,837 with a standard deviation of $1500 according to the U.S. Department of Education. The dean of a graduate school at a large state university feels that Ph.D. students in his state earn more than this. He surveys 44 randomly selected students and finds their average salary is $13,445. With α = 0.05, is the dean correct?