One Proportion Confidence Interval

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?

• (0.591, 0.812)

• (0.615, 0.805)

• (0.584, 0.830)

• (0.621, 0.780)

Tags

CCSS.HSS.IC.B.4

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?

• 0.316 < p < 0.384

• 0.305 < p < 0.395

• 0.309 < p < 0.391

• 0.321 < p < 0.379

Tags

CCSS.HSS.IC.B.4

A sample of 400 racing cars showed that 80 cars cost over $700,000. What is the 99% confidence interval of the true proportion of cars costing over $700,000?

• 0.023 < p < 0.045

• 0.001 < p < 0.005

• 0.148 < p < 0.252

• 0.566 < p < 0.693

Tags

CCSS.HSS.IC.B.4

If 827 represents "no" voters out of 2584, construct a 95% confidence interval for the "no" group.

• [.302,.338]

• [.300,.340]

• [.288,.352]

• [.298,.342]

Tags

CCSS.HSS.IC.B.4

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

• 0.68

• 0.055

• 0.028

• 0.79

• 0.735

Tags

CCSS.HSS.IC.B.4

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

Tags

CCSS.HSS.IC.B.4

Fatimah wants to estimate the proportion of students who ate breakfast every day last week. She takes a simple random sample of 80 of the 1000 students at her school and finds that 20 of those sampled at breakfast every day last week.

Based on this sample, which of the following is a 95% confidence interval for the proportion of all students at the school who ate breakfast every day last week? 

• 20 ± 0.080

• 20 ± 0.095

• 0.25 ± 0.080 

• 0.25 ± 0.095 

Tags

CCSS.HSS.IC.B.4

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)

Tags

CCSS.HSS.IC.B.4

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.

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CCSS.HSS.IC.B.4

A survey of 800 women shoppers found that 17% of them shop on impulse.  What is the 98% confidence interval for the true proportion of women shoppers who shop on impulse? 

• 0.148 < p < 0.192
• 0.136 < p < 0.204
• 0.144 < p < 0.196
• 0.139 < p < 0.201

Tags

CCSS.HSS.IC.B.4