In: Statistics and Probability
QUESTION: Using Microsoft® Excel®, run a chi square Goodness of Fit test to determine whether these observed starting salaries are significantly different. What do the findings tell you?
Expected Salaries |
Observed Salaries |
|
Applicant 1 |
$20,000 |
$17,500 |
Applicant 2 |
$20,000 |
$20,000 |
Applicant 3 |
$20,000 |
$22,000 |
Applicant 4 |
$20,000 |
$20,500 |
Applicant 5 |
$20,000 |
$20,000 |
Hello Sir/Mam
Chi - square Goodness of Fit test using excel
Let the null hypothesis be that the actual salaries matches with expected salaries.
i.e. H0 : X2 = 0
Expected Salaries | Observed Salaries | Formulas used | |
Applicant 1 | 20000 | 17500 | |
Applicant 2 | 20000 | 20000 | |
Applicant 3 | 20000 | 22000 | |
Applicant 4 | 20000 | 20500 | |
Applicant 5 | 20000 | 20000 | |
p-value using chi-square goodness of fit test | 2.6211E-112 | =CHISQ.TEST(G8:G12,F8:F12) |
The same value can also be found using:
Expected Salaries | Observed Salaries | [(Observed-Expected)^2]/ Expected | |
Applicant 1 | 20000 | 17500 | 312.5 |
Applicant 2 | 20000 | 20000 | 0 |
Applicant 3 | 20000 | 22000 | 200 |
Applicant 4 | 20000 | 20500 | 12.5 |
Applicant 5 | 20000 | 20000 | 0 |
Total | 525 |
Now, degree of freedomm = (n-1) = (5-1) = 4
Using, excel formula : "=CHISQ.DIST.RT(525,4)", we will find the same p-value, i.e. 2.6211E-112.
Now, Chi-Square Critical = CHISQ.INV.RT(0.05,4) = 9.4877
Now, p-value < , we can reject the null hypothesis and hence, we can say that the starting salaries are significantly different.
I hope this solves your doubt.
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