Hypothesis test scenario:

Each week I am learning more and more and never in my life have I thought about hypothesis testing. Based off a "previous" study of cordless Ryobi Power tools battery life. Given a sample mean (xbar) 3.0 and a population standard deviation sigma of 1.2 with n= 80 values, find the Z and P value. Previous data says that the population mean (u) for cordless Ryobi Power Tool battery life is 2.8 hrs. For this exercise I wanted to test the claim that u<2.8.