5. Question : In the past, of all the students enrolled in "Basic Business Statistics" 10% earned A's, 20% earned B's, 30% earned C's, 20% earned D's and the remaining 20% either failed or withdrew from the course.
Dr Johnson is a new professor teaching "Basic Business Statistics" for the first time this semester. At the conclusion of the semester, in Dr. Johnson's class of 60 students, there were 10 A's, 20 B's, 20 C's, 5 D's and 5 W's or F's.
Assume that Dr. Johnson's class constitutes a random sample. Dr Johnson wants to know if there is sufficient evidence to conclude that the grade distribution of his class is different than the historical grade distribution.
Use a = .05, and determine if the grade distribution for Dr. Johnson's class is different than the historical grade distribution.
Reject the null hypothesis at the 5% level of significance because 16.4 > 9.48 Therefore there is a difference between the historical grade distribution and Dr. Johnson's