According to The Washington Post, 72% of high school seniors have a driver’s license. Suppose we take a random sample of 100 high school seniors and find the proportion who have a driver’s license.

a. What value should we expect for our sample proportion?

b. What is the standard error?

c. Use your answers to parts a and b to complete this sentence: We expect _____% to have their driver’s license, give or take _____%.

d. Suppose we increased the sample size from 100 to 500. What effect would this have on the standard error? Recalculate the standard error to see if your prediction was correct.