In: Statistics and Probability
The number of men and women among professors in math, physics, chemistry. linguistics, and English departments from a SRS of small colleges were counted, and the results are shown in the table below
Department | Math | Physics | Chemistry | Linguistics | English |
Men | 43 | 81 | 30 | 20 | 29 |
Women | 5 | 5 | 8 | 14 | 23 |
Test the claim that the gender of a professor is independent of the department. Use the significance level alpha = 0.025
a) The test statistic is chi squared =
b) The critical value is chi squared =
c) Is there sufficient evidence to warrant the rejection of the claim that the gender of a professor is independent of the department? Yes or no?
Ans:
H0: the gender of a professor is independent of the department.
Ha: the gender of a professor is not independent of the department.
Observed(fo) | ||||||
Department | Math | Physics | Chemistry | Linguistics | English | Total |
Men | 43 | 81 | 30 | 20 | 29 | 203 |
Women | 5 | 5 | 8 | 14 | 23 | 55 |
Total | 48 | 86 | 38 | 34 | 52 | 258 |
Expected(fe) | ||||||
Department | Math | Physics | Chemistry | Linguistics | English | Total |
Men | 37.77 | 67.67 | 29.90 | 26.75 | 40.91 | 203 |
Women | 10.23 | 18.33 | 8.10 | 7.25 | 11.09 | 55 |
Total | 48 | 86 | 38 | 34 | 52 | 258 |
Chi square=(fo-fe)^2/fe | ||||||
Department | Math | Physics | Chemistry | Linguistics | English | Total |
Men | 0.725 | 2.627 | 0.000 | 1.704 | 3.470 | 8.526 |
Women | 2.676 | 9.697 | 0.001 | 6.290 | 12.806 | 31.470 |
Total | 3.401 | 12.324 | 0.002 | 7.994 | 16.276 | 39.996 |
a)Test statistic:
Chi square=39.996
b)df=(2-1)*(5-1)=4
critical chi square value=CHIINV(0.025,4)=11.143
c)As,test statistic is greater than critical chi square,we reject the null hypothesis.
Yes,there is sufficient evidence to warrant the rejection of the claim that the gender of a professor is independent of the department.