In: Statistics and Probability
13-22: A loan officer wished to determine if the marital status of loan applicants was independent of the approval loans. The following table represents the result of her survey:
Approved Rejected
Single 213 189
Married 374 231
Divorced 358 252
Claim : To test whether that the marital status of loan applicants was independent of the approval loans or not
Hypothesis : Ho: marital status of loan applicants and the approval loans are independent
H1: marital status of loan applicants and the approval loans are dependent
Test statistics :
Where
Approved | Rejected | Total | |
single | 213 | 189 | 402 |
married | 374 | 231 | 605 |
divorced | 358 | 252 | 610 |
Total | 945 | 672 | 1617 |
we get the expected frequencies as
Simmilarly , E12 = 167.06, E21= 353.57, E22=251.43 , E31=356.49 and E32=253.51
we can calculate test statistics as
Oi | Ei | (Oi-Ei) | (Oi-Ei)^2 | (Oi-Ei)^2/E |
213 | 234.94 | -21.94 | 481.3636 | 2.04887886 |
189 | 167.06 | 21.94 | 481.3636 | 2.88138154 |
374 | 353.57 | 20.43 | 417.3849 | 1.18048732 |
231 | 251.43 | -20.43 | 417.3849 | 1.66004415 |
358 | 356.49 | 1.51 | 2.2801 | 0.00639597 |
252 | 253.51 | -1.51 | 2.2801 | 0.00899412 |
Total | 7.79 |
we get test statistics =
Pvalue : By using excel we get exact pvalue
Excel command is =CHIDIST(X,Degrees of freedom)
=CHIDIST(7.79,2)
=0.0203
...............( Given)
Decision Rule : We Fail to reject Ho
Conclusion : There is sufficient evidence to conclude that marital status of loan applicants and the approval loans are independent