Chapter 8, Problem 118H

Suppose that the insurance companies did do a survey. They randomly surveyed 400 drivers and found that 320 claimed they always buckle up. We are Interested in the population proportion of drivers who claim they always buckle up.

a. i. $\bar{x}$ ______

ii. n=______ .

iii. P’ _______

b. Define the random variables X and P. in words.

c. Which distribution should you use for this problem? Explain your choice.

d. Construct a 95°o confidence interval for the population proportion who claim they always buckle up.

i. State the confidence Interval.

ii. Sketch the graph.

iii. Calculate the error bound.

e. If this survey were done by telephone, list three difficulties the companies might have in obtaining random results.