One Proportion Confidence Interval

Given the 95% confidence interval (0.68, 0.79), what is the point estimate?

• 0.68

• 0.055

• 0.028

• 0.79

• 0.735

Given the 95% confidence interval (0.68, 0.79), what is the margin of error?

• 0.68

• 0.055

• 0.028

• 0.79

• 0.735

A study is used to create a 90% confidence interval for the Presidential approval rating. The resulting interval is (0.48, 0.52). Interpret this interval in context.

• We are 90% confident that the true proportion of people who approve of the President’s job performance is between 0.48 and 0.52.

• 90% of people surveyed will place their proportion of Presidential approval between 0.48 and 0.52.

• If we survey 100 people, 50 of them will say they approve of the President’s job performance.

• A survey of Presidential approval will always be 90% confident of the true proportion.

A random sample of 100 WHS students found that 53 of them were in possession of a pencil. What is the p-hat for this sample?

• 0.53
• 0.5
• 0.47
• 1

For a sample, the 95% confidence interval is (0.202, 0.482).

What is the point estimate, p̂, of this sample?

• 0.28

• 0.14

• 0.342

• 0.684

For a sample, the 95% confidence interval is (0.202, 0.482).

What is the margin of error of this sample?

• 0.28

• 0.14

• 0.342

• 0.684

A recent study of 750 Internet users in Europe found that 35% of Internet users were women.  What is the 95% confidence interval of the true proportion of women in Europe who use the Internet? 

• 0.321 < p < 0.379
• 0.316 < p < 0.384
• 0.309 < p < 0.391
• 0.305 < p < 0.395

It was found that in a sample of 90 teenage boys, 70% of them have received speeding tickets.  What is the 90% confidence interval of the true proportion of teenage boys who have received speeding tickets? 

• (0.621, 0.780)
• (0.591, 0.812)
• (0.584, 0.830)
• (0.615, 0.805)

An airline transports over 10,000 passengers daily, and the airline is curious what proportion of their passengers use mobile boarding passes instead of paper passes.  They take a simple random sample of 80 passengers and find that 60 of them use mobile boarding passes.

Based on this sample, which of the following is a 95% confidence interval for the proportion of passengers who use mobile boarding passes?

• (0.625, 0.875)

• (0.637, 0.863)

• (0.655, 0.845)

• (0.670, 0.830)