8.4 Confidence Intervals for Proportions

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

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.ID.B.5

A survey of 80 recent fatal traffic accidents showed that 46 were alcohol-related. Find the 98% CI.

• (-30.01, 122.01)
• (45.87, 46.13)
• (.45, .70)
• (.29, .55)

Tags

CCSS.HSS.IC.B.4

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

• [.300,.340]
• [.298,.342]
• [.302,.338]
• [.288,.352]

Tags

CCSS.HSS.IC.B.4

Find the minimum sample size needed to be 4% within the true proportion if you are 95% confident and p-hat = 0.6

• 12
• 6
• 961
• 577

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

A nutritionist found that in a sample of 80 families, 22% said they are apples at least once a week. Construct the 90% CI for the population proportion.

• (0.144, 0.296)
• (0.190, 0.250)
• (0.704, 0.856)
• (0.129, 0.311)

Tags

CCSS.HSS.IC.B.4

A medical researcher wishes to determine the percentage of females who take vitamins. She wishes to be 99% confident that the estimate is with 2 percentage points of the population proportion. How large should the sample size be, at a minimum, if a recent study showed that 25% of females take vitamins?

• 3012
• 3111
• 4011
• 5613