1.

In a simple random sample of 1600 adult Americans, the proportion of people who travel on vacation every year was found to be 0.25 or (25%).

Find a 90% confidence interval for estimating the proportion of all adult Americans who travelon vacation every year.

2.

In a simple random sample of 1600 adult Americans, the proportion of people who travel on vacation every year was found to be 0.25 or (25%).

Find the margin of error, using a 90% confidence level, for estimating the proportion of all adult Americans who travel on vacation every year.

3

A math professor observes that approximately 80% of students at a certain college pass the final exam.

Find the approximate probability that more than 84% of 120 randomly sampled students taking the math final exam will pass it.

4.

A math professor observes that approximately 80% of students at a certain college pass the final exam.

Find the approximate probability that lass than 84% of 120 randomly sampled students taking the math final exam will pass it.