User manual - Examples 2

examples

Example If 132 of 200 male voters and 90 of 150 female voters favor a certain

candidate running for governor of Texas, find a 99% confidence

interval for the difference between the actual proportions of male and

female voters who favor the candidate.

Procedure

1 m STAT2

2 4(INTR) b(Z)e(2-Prop)

3 .jjw

bdcw

caaw

jaw

bfaw

1(None)c

4 1(CALC)

Result Screen

Let p1 the actual propotion of male voters who favor the candidate.

Let p2 the actual propotion of female voters who favor the candidate.

Thus, the 99% confidence interval for (p1-p2) is -0.074<p1-p2<0.194.