review 6.1 CI for Large Sample Means

The standard IQ test has a mean of 97 and a standard deviation of 18. We want to be 95% certain that we are within 5 IQ points of the true mean. Determine the required sample size.

• 8

• 50

• 1

• 147

Tags

CCSS.HSS.IC.B.4

The standard IQ test has a mean of 95 and a standard deviation of 17. We want to be 95% certain that we are within 2 IQ points of the true mean. Determine the required sample size.

• 1

• 373

• 278

• 17

Tags

CCSS.HSS.IC.B.4

A nurse at a local hospital is interested in estimating the birth weight of infants. How large a sample must she select if she desires to be 99% confident that the true mean is within 3 ounces of the sample mean? The standard deviation of the birth weights is known to be 8 ounces.

• 47

• 6

• 48

• 7

Tags

CCSS.HSS.IC.B.4

A nurse at a local hospital is interested in estimating the birth weight of infants. How large a sample must she select if she desires to be 99% confident that the true mean is within 3 ounces of the sample mean? The standard deviation of the birth weights is known to be 6 ounces.

• 5

• 26

• 6

• 27

Tags

CCSS.HSS.IC.B.4

A nurse at a local hospital is interested in estimating the birth weight of infants. How large a sample must she select if she desires to be 99% confident that the true mean is within 3 ounces of the sample mean? The standard deviation of the birth weights is known to be 9 ounces.

• 60

• 8

• 7

• 59

Tags

CCSS.HSS.IC.B.4

A sample size of n = 64 is drawn from a population whose standard deviation is σ = 5.6.

Find the margin of error for a 99% confidence interval for µ.

• 1.672

• 1.798

• 1.803

• 1.594

Tags

CCSS.HSS.IC.B.4

A sample of 30 women finds the mean height to be 62.3 in and the standard deviation to be 1.5 in. Find the margin of error of women's heights with a 95% CL.

• 1.699
• 0.56
• 0.537
• 19.325

Tags

CCSS.HSS.IC.B.4

An IQ test was given to a simple random sample of 75 students at a certain college. The sample mean score was 105.2. Scores on this test are known to have a standard deviation of 10. It is desired to construct a 90% confidence interval for the mean IQ scores of the students at the college. Find the Margin of Error

• 1.751

• 1.634

• 1.899

• 1.909

Tags

CCSS.6.SP.B.5C

Find the value of z_c for a 90% confidence interval.

• -1.96 
• 1.645
• 1.440
• -1.598

Tags

CCSS.HSS.ID.A.4

The lifetime of a certain type of batter is known to be normally distributed with a standard deviation of 20 hours. A sample of 50 batteries had a mean lifetime of 120.1 hours. It is desired to construct a 99% confidence interval for the mean lifetime of this type of battery.

What is the Confidence Interval to one decimal place?

• (114.5, 125.6)

• (112.8, 127.4)

• (112.82, 127.38)

• (114.56, 125.64)

Tags

CCSS.HSS.IC.B.4