Question

The following information is required to answer questions 8-10. A random sample of 22 fifth grade pupils have a grade point average (GPA) of 5.0 in maths with a variance of 0.21, where marks range from 1 (worst) to 6 (excellent). The GPA of all fifth grade pupils of the last five years is 4.7. Is the GPA of the 22 pupils different from the populations’ GPA?

8. Approximately what is the value of the obtained t-statistic?

1. 3.06
2. 1.99
3. 2.13
4. 0.57

9. Assuming an alpha level of .01, what is the probability of making a Type I error?

1. .05
2. .99
3. .01
4. .001

10. If we increased our alpha level to .05, what would happen to the probability of making a Type II error?

1. It would increase
2. It would be 0.95
3. It would be equal to the probability of making a Type I error
4. It would decrease

Answer 1

8.

= 5

= 0.21

= 4.7

n = 22

9. Assuming an alpha level of .01, what is the probability of making a Type I error?

P[ type I error ] = alpha level = 0.01

c 0.01

10. If we increased our alpha level to .05, what would happen to the probability of making a Type II error?

d. It would decrease

The type I and type II probability are inversely proportional