Dr. Snyder teaches a large introductory statistics course. In the past, the proportion of students that receive a grade of A is 0.20. The proportion that receives a B is 0.30. The proportion that receives a C is 0.30. The proportion that receives a D is 0.10. The proportion that receives an F is 0.10. This year, there were 200 students in the class and they received the following grades.

A B C D F
Number 56 74 60 9 1

The expected numbers of counts are for A,B,C,D,E:
Answer

Multiply each proportion by 200:

A = 200 * .20 = ?
B = 200 * .30 = ?
C = 200 * .30 = ?
D = 200 * .10 = ?
E = 200 * .10 = ?

I'll let you finish the calculations.

The last one should be F instead of E:

F = 200 * .10 = ?

Sorry for any confusion.

To calculate the expected numbers of counts for each grade, we can use the proportions given in the problem statement and multiply them by the total number of students.

In this case, there were 200 students in the class. We can multiply this number by the proportion of students that receive each grade to get the expected number of counts for each grade.

Expected number of students receiving an A = 0.20 * 200 = 40
Expected number of students receiving a B = 0.30 * 200 = 60
Expected number of students receiving a C = 0.30 * 200 = 60
Expected number of students receiving a D = 0.10 * 200 = 20
Expected number of students receiving an F = 0.10 * 200 = 20

Therefore, the expected numbers of counts for each grade are:
A: 40
B: 60
C: 60
D: 20
F: 20