In: Statistics and Probability
A police department is interested in learning if men or women do better as a result of their training course. They administer a skills test to 60 newly trained officers: 30 males and 30 females. Use the data below to establish hypotheses and test them using a chi-square test. State the decision with regard to whether the H0 is ultimately rejected or retained.
Test Scores |
Customary Course |
New Course |
Excellent |
7 |
13 |
Good |
15 |
15 |
Unsatisfactory |
8 |
2 |
let us consider the null and alternative hypothesis is
Ho:test score is independent of training course
Ha:test score is dependent on training course
Observed Frequencies | ||||||
Column variable | Calculations | |||||
test scores | Customary Course | New Course | Total | fo-fe | ||
Excellent | 7 | 13 | 20 | -3 | 3 | |
Good | 15 | 15 | 30 | 0 | 0 | |
Unsatisfactory | 8 | 2 | 10 | 3 | -3 | |
Total | 30 | 30 | 60 | |||
Expected Frequencies | ||||||
Column variable | ||||||
test scores | Customary Course | New Course | Total | (fo-fe)^2/fe | ||
Excellent | 10 | 10 | 20 | 0.9 | 0.9 | |
Good | 15 | 15 | 30 | 0 | 0 | |
Unsatisfactory | 5 | 5 | 10 | 1.8 | 1.8 | |
Total | 30 | 30 | 60 | |||
Data | ||||||
Level of Significance | 0.05 | |||||
Number of Rows | 3 | |||||
Number of Columns | 2 | |||||
Degrees of Freedom | 2 | |||||
Results | ||||||
Critical Value | 5.991465 | |||||
Chi-Square Test Statistic | 5.4 | |||||
p-Value | 0.067206 | |||||
Do not reject the null hypothesis |
\
the value of chi square test is 5.4
p value is 0.0672
since p value is greater than 0.05 so we do not reject Ho and concluude that test score is independent of training course