A researcher randomly surveyed 300 high school seniors and determined 225 stated they drive a car to high school. We are interested in the population proportion of seniors who drive a car to high school.

a. Define the random variable X for this problem in words.

b. Define the random variable P for this problem in words.

c. Construct a 90% confidence interval (CI) for the population proportion of high school seniors who claim to drive a car to high school. Round your CI to FOUR decimal places.

D.Is it reasonable to conclude at least 80% of seniors drive a car to high school?

For C I got 0.75-1.645((0.75)(1-0.75)/300 = 0.7089

and i got 0.7911 for the +. which the answers i got are 0.7089 and 0.7911 thats all i got can someone help and explain to me.