In: Statistics and Probability
Complete this exercise using the Seven Steps to Hypothesis Testing.
A university president collects data showing the number of absences over the past academic year for a random sample of 6 professors in the College of Engineering. He does the same for a random sample of 9 professors in the College of Business and for a random sample of 8 professors in the College of Fine Arts. Assuming an alpha of .05, is there a significant difference in absences among colleges?
There are no data values but i am giving you example, follow the steps with your values
Engineering | Business | Fine Arts | ||
8 | 5 | 9 | ||
10 | 7 | 10 | ||
6 | 6 | 10 | ||
8 | 7 | 9 | ||
4 | 7 | 7 | ||
8 | 6 | 5 | ||
8 | 13 | |||
8 | 7 | |||
1 | ||||
Mean | 7.333 | 6.111 | 8.75 | |
SD | 2.066 | 2.147 | 2.435 | |
n | 6 | 9 | 8 | 23 |
SUM(X^2) | 344 | 373 | 654 | 1371 |
SUM(X) | 44 | 55 | 70 | 169 |
SS = (SUM(X^2)-SUM(X)^2/n) | 21.3333333 | 36.8888889 | 41.5 | 99.72222222 |
df | SS | MS | F | |
Between | 2 (k-1) | 29.495 (SSB = SST-SSW) | 14.7475(MSB = SSB/df1) | 2.957722468 (F = MSB/MSW) |
Within | 20 (n-k) | 99.722 (SSW=Total SS) | 4.9861 (MSW = SSW/df2) | |
Total | 22 (n-1) | 129.217 (SST=Total(SUM(X^2))-Total(SUM(X))^2/Total(n)) |
Hypothesis:
1)Ho: μ1 = μ2 = μ3
2)Ha: Not all means are equal
3)Rejection region:
df1 = 2 and df2 = 20
F critical = 3.493 (Use F table)
If F stat > F critical, reject H0
4)Test:
F = 2.9577
5)Decision:
F = 2.958 ≤ Fc = 3.493, Do not reject H0
6)P value = 0.0749 (Use F table)
P value > 0.05, Do not reject H0
7)Conclusion:
There is not enough evidence to conclude that there a significant difference in absences among colleges at 5% significance level