7) A statistics professor is examining class performance for students this term. Usually, she expects a class mean of 78% with o = 4.5% . This term however her students appear to not be doing as well. Using a 5% level of significance (meaning a = 0.5), can it be concluded that the mean grade this term is lower than usual if the size of the class is 25, and the average is 76%? SHOW ALL WORK to answer this. To help you get started the null hypothesis and alternative hypothesis are given below. (5 marks) Ho = 78 Ha