You hypothesize that, when both a man and a woman are in the front seat of a car, the man is more likely to be driving than the woman.
The null hypothesis is that the man and the woman are driving equally often.
You decide to test the hypothesis by observing 20 cars with both a man and a woman in the front, and counting how many of those have a man driving.
Say that men are really driving 70% of the time. Using a one tailed test at ?= .05, how many men have to be driving in order for you to be able to reject the null hypothesis? (In other words, at least what number of cars must be driven by men for you to reject the null?)
If men are really driving 70% of the time, using a one tailed test at ?= .05, what will your power be if you observe 20 cars? (give a numeric answer to at least 3 decimal places)