Question

Consider the following data collected in two recent surveys of whether voters in cities A and B favor a ballot proposition in the next election. City Sample Size In Favor A 615 463 B 585 403 Suppose you're going to find a confidence interval for the difference between the population proportions in the two cities. What's the standard error of the estimate of the difference between the two proportions?

Answer 1

Answer:

Standard error of the estimate of the difference between the two proportions=0.0259

Step-by-step explanation:

Given that the following data collected in two recent surveys of whether voters in cities A and B favor a ballot proposition in the next election.

City                         A                  B            Total

Sample size          615            585             1200

Favour X               463           403               866

Proportion p         0.7528     0.6889        0.7217

Std error for difference

= $\sqrt{p(1-p)(\frac{1}{n_1} }+ \frac{1}{n_2}$

p =0.7217

1-p = 0.2783

by substituting p and n1 = 615 and n2 = 585 we get

Std error = 0.0259

Standard error of the estimate of the difference between the two proportions=0.0259