One Proportion Z Interval

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?

• 0.001 < p < 0.005

• 0.566 < p < 0.693

• 0.148 < p < 0.252

• 0.023 < p < 0.045

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

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)

125 people from the Dallas area were asked if they believed in extra-terrestrial beings. 98 responded yes. Which interval below represents a 90% confidence interval for the true proportion of all people living in the Dallas area who believe in extra-terrestrial beings?

• (0.723 , 0.844)

• (0.712 , 0.856)

• (0.737 , 0.831)

• (0.689 , 0.879)

88 out 150 students say they like the chicken tenders served in the cafeteria. What is a 95% confidence interval for the true proportion of all students who like chicken tenders (3 decimal places)

• (0.507 , 0.665)

• (0.520 , 652)

• (0.483 , 0.690)

• (0.535 , 0.638)

88 out 150 students say they like the chicken tenders served in the cafeteria. An 85% confidence interval for this sample is (0.529 , 0.644). What does this mean.

• we are 85% confident that the true proportion of all Woodrow students who like chicken tenders is between 52.9% and 64.4%.

• 85% of all Woodrow students like chicken tenders.

• 85% of all samples would have phats between 52.9% and 64.4%.

• 85% of all Woodrow students like chicken tenders between 52.9% and 64.4% of the time.

A surprising number of young adults (ages 19 to 25) still live in their parents' homes. The National Institutes of Health (NIH) surveyed independent 2253 men and 2626 women in this age group. The survey found that 986 of the men and 923 of the women lived with their parents. Find a 99% confidence interval for difference in the true proportion of men and women aged 19 to 25 who live in their parents' home.

• (0.051, 0.123)

• (0.059, 0.114)

• (0.064, 0.11)

• (0.069, 0.104)

Given an SRS of 30 math scores, what is an estimate of the true proportion of students in this population that score over 650 in math?

• One-Proprtion z-Test

• One-Proportion z-Interval

• One-Sample t-Interval

• One-Sample t-Interal on Matched Pairs

Which test or interval would be appropriate for this scenario?

• One-Proportion Z-Test/Interval

• Two-Proportion Z-Test/Interval

• One-Sample t-Test/Interval

• Matched-Pairs t-Test/Interval

• Two-Sample t-Test/Interval

Which test or interval would be appropriate for this scenario?

• One-Proportion Z-Test/Interval

• Two-Proportion Z-Test/Interval

• One-Sample t-Test/Interval

• Matched-Pairs t-Test/Interval

• Two-Sample t-Test/Interval