In class of remedial English taught by lecture method, 52 out of 75 students completed the course with a passing grade. In same course with computer-assisted instruction, 69 out of 95 completed course with passing grade. At .05 level, is there a significant difference in passing rates for the 2 different methods of instruction?
Solution: We use z-test for proportions to test
The z-statistics is computed as
Replacing the values at the z-statistics we get that
The critical values for the 0.05 level are. Therefore, we cannot reject the null hypothesis, which means that we don’t have enough evidence to claim that there is a significant difference in passing rates for the 2 different methods of instruction