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

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 preliminary study suggests that 87% of people agree on an issue. How large must your sample size be so you could be within ± 3% of p calculate at 90% confidence?

• 7

• 466

• 5

• 338

Tags

CCSS.HSS.IC.B.4

Find the critical value, z* for 97%

• 1.88

• 2.17

• -1.88

• -2.17

Tags

CCSS.HSS.ID.A.4

Which confidence would result in a wider interval (assuming nothing else changed), 91% or 97%?

• 97%, z* is larger for higher confidence intervals

• 97%, the standard error is larger for higher confidence intervals

• 91%, z* is larger for lower confidence intervals

• 91%, the standard error is smaller for lower confidence intervals

Tags

CCSS.HSS.IC.B.4

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

Tags

CCSS.HSS.IC.B.4

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

Tags

CCSS.HSS.IC.B.4

The symbol for the sample proportion is __________.

• Z^*

• p̂

• E

• p

Tags

CCSS.HSS.IC.B.4