In: Statistics and Probability
The dean of a University estimates that the mean number of classroom hours for full time faculty is 11.0. As a member of sydent council, you want to test the claim. A sample of the number of classroom hours for 8 full-time faculty is shown below.
11.8 6.4 8.6 10.4 12.6 13.6 7.9 9.1
At the .01 level of significance, is the Dean’s claim valid? Use the P-value approach. Clearly state the null and alternative hypotheses. Locate the claim and state the decision.
Solution:
x | x2 |
11.8 | 139.24 |
6.4 | 40.96 |
8.6 | 73.96 |
10.4 | 108.16 |
12.6 | 158.76 |
13.6 | 184.96 |
7.9 | 62.41 |
9.1 | 82.81 |
∑x=80.4 | ∑x2=851.26 |
Mean ˉx=∑xn
=11.8+6.4+8.6+10.4+12.6+13.6+7.9+9.1/8
=80.4/8
=10.05
Sample Standard deviation S=√∑x2-(∑x)2nn-1
=√851.26-(80.4)28/7
=√851.26-808.02/7
=√43.247
=√6.1771
=2.4854
This is the two tailed test .
The null and alternative hypothesis is ,
H0 : = 11.0
Ha : 11.0
Test statistic = t
= ( - ) / s / n
= (10.05-11.0) / 2.48 / 8
= −1.083
Test statistic = t = −1.083
P-value =0.3145
= 0.01
P-value >
0.3145 > 0.01
Fail to reject the null hypothesis .
There is insufficient evidence to suggest that