33
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 .jj
w
bdc
w
caa
w
ja
w
bfa
w
1
(None)
c
4
1
(CALC)
Result Screen
Let p
1
the actual propotion of male voters who favor the candidate.
Let p
2
the actual propotion of female voters who favor the candidate.
Thus, the 99% confidence interval for (p
1
-p
2
)
is -0.074<p
1
-p
2
<0.194.
