Question

A statistics teacher claims that, on average, 20% of her students get a grade of A, 35% get a B, 25% get a C, 10% get a D, and 10% get an F. The grades of a random sample of 100 are shown below. Use a = 0.05 to test the claim that the grades follow the distribution claimed by the teacher.

Grade                # of Students

A                      29

B                      42

C                      20

D                        5

F                         4

Answer 1

P value and statistical significance:
  Chi squared equals 12.550 with 4 degrees of freedom.
  The two-tailed P value equals 0.0137

Since the P-value (0.0137 ) is less than the significance level (0.05), we cannot accept the null hypothesis.

The null hypothesis for this test is that there is no relationship and we are rejecting null hypothesis

So the claim that the grades follow the distribution claimed by the teacher is true and both the observed and claimed results are related