Use the normal distribution to find a confidence interval for a difference in proportions p1 - p2 given the relevant sample results. Assume the results come from random samples.
A 90% confidence interval for p1 - p2 given counts of 148 yes out of 170 sampled for Group 1 and 12 yes out 110 sampled for Group 2.
Give the best estimate for p1 - p2, the margin of error, and the confidence interval.
best estimate = ?
margin of error = ?
confidence interval is ? to ?