To learn whether such a difference is unusually high, we will find the Z-score of the difference. To find a Z-score of a difference in sample proportions, we must determine the mean of differences, and the standard deviation (standard error) of differences. The mean of differences (mean difference) between two sample proportions is the difference between their means, .1 2 5 What are the population proportions and the mean of differences between sample proportions? Women's population proportion: ______1 = Men's population proportion: ______2 = Mean difference: ______1 2 = The standard deviation (i.e. standard error) of sample proportions is , so the variance is the (1 ) square of this, . From what we learned above, the variance of all differences between two (1 ) sample proportions is the sum of the individual variances, , and the standard 1(1 1) 1 + 2(1 2) 2 deviation (or standard error) is the square root of this: . 1(1 1) 1 + 2(1 2) 2 6 Compute the standard error of differences between sample proportions. Round your answer to three decimal places. standard error: ________________ 1(1 1) 1 + 2(1 2) 2