The examinations in a large accounting class are scaled after grading so that the mean score is 50 The professor thinks that one teaching assistant is a poor teacher and suspects that his students have a lower mean score than the class as a whole The TA s students this semester can be considered a random sample from the population of all students in the course so the professor compares their mean score with 50 State the hypotheses Ho and Ha a Ho 50 Ha 50 b Ho 50 H the sample s mean a c Ho 50 Ha 50 d Ho 50 Ha 50