Honestly I have no idea how to do these I dont even know where to start please help

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 rest 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.


At α = .05, the null hypothesis is rejected. Make a one-sentence managerial conclusion.

You can use the chi-square goodness-of-fit test. This is similar to the example here, your expected value is the total number 60 times the proportion in each group.