A railway company used 2 types of wheel mounts that differ inthe way they handle track irregularities: type A and type B. Thefollowing data gives the repair records for 2 types over a 1 yearperiod:
| # of cars | # needing service |
| Type A | 150 | 20 |
| Type B | 180 | 18 |
Test for the difference between population proportionsPA and PB.Useα = 0.02.
