1. Day 2 proportions (independent samples)
9-5
Day 2
proportions
(independent samples)

2. Difference in Proportions
Two independent binomial experiments

3. Difference of Proportions (cont)
Pooled estimate for the population probability of success

4. Example
A question about spending more federal tax money on the arts was asked by a research group. Of a random sample of n1=93 politically conservative voters, r1 = 21 responded yes. Another sample of 83 politically moderate voters showed that r2 = 22 voted yes. Does this information indicate that the proportion of conservative voters inclined to spend more federal tax money on funding the arts is less than the proportion of moderate voters? Use 5% level of confidence.