Chapter 11, Problem 9P

Use the following information to answer the next five exercises: A teacher predicts that the distribution of grades on the final exam will be and they are recorded in Table 11.27.

Grade	Proportion
A	0.25
B	0.30
C	0.35
D	0.10

The actual distribution for a class of 20 is in Table 11.28.

Grade	Frequency
A	7
B	7
C	5
D	1

Table 11.28.

d f = ______