A large company is considering installing charging stations for electric cars in their company parking lots. Suppose that 1.5% of employees at the main office have electric cars and 2% of employees at the branch
office have electric cars.
The company wonders whether there is greater need for the stations at the main office. They plan to take
separate random samples of 100 employees from the main office and 50 employees from a branch office.
Then they will look at the difference in the sample proportions (ÔM - PB).
What will be the shape of the sampling distribution of PM - PB, and why?