Estimating with 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)

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]

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.A.1

CCSS.HSS.IC.B.4

CCSS.HSS.ID.A.4

Which of the following does NOT have an affect on the width of a confidence interval?

• Sample mean
• t*
• Sample standard deviation
• Sample size

Which of the following changes to a study would result in a narrower confidence interval?

• increasing the confidence level, increasing the sample size
• decreasing the confidence level, decreasing the sample size
• increasing the confidence level, decreasing the sample size
• decreasing the confidence level, increasing the sample size.

Tags

CCSS.HSS.IC.B.4

A survey of 280 homeless persons showed that 63 were veterans.  Construct a 90% confidence interval for the proportion of homeless persons who are veterans.

• (0.161, 0.289)
• (0.176, 0.274)
• (0.184, 0.266)
• (0.167, 0.283)

In a survey of 2480 golfers, 15% said they were left-handed.  The survey's margin of error was 3%.  Construct a confidence interval for the proportion of left-handed golfers.

• (0.18, 0.21)
• (0.12, 0.18)
• (0.12, 0.15)
• (0.11, 0.19)

You take a poll and find that 34% of the 100 people you asked dislike school lunches.  Using a 95% confidence level, what is the margin of error?

• 0.093
• 0.047
• .034
• .34

28% of all Woodrow students believe Monday will be snow day. You take a sample of 50 students and find that 15 of them believe Monday will be a snow day. What does 50 represent? 

• n
• P
• phat
• standard deviation