6-5 Quiz: Confidence Intervals for Means

A sample of 20 cupcakes found the interval for average calories to be (150, 350). Which is the correct interpretation of the 95% confidence interval?

• We are 95% confident that the true mean caloric content can be found with a sample of 150 to 350 cupcakes.

• We are 95% confident that the interval (150, 350) captures the true average caloric content.

• We are 95% confident that a sample of 20 cupcakes will find 250 calories per cupcake.

• None of these are correct.

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

Thirty randomly selected students took the calculus final. If the sample mean was 92 and the standard deviation was 9.4, construct a 99 percent confidence interval for the mean score of all students from which the sample was gathered.

• 89.08 < μ < 94.92

• 87.27 < μ < 96.73

• 87.29 < μ < 96.71

• 87.77 < μ < 96.23

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

CCSS.HSS.ID.A.4

In a crash test of 15 troopers, collision repair costs are found to have a distribution that is approximately normal, with a mean of $1800 and a standard deviation of $950. Construct a 99% confidence interval for the repair cost for the population.

• (1070, 2530)

• (1273, 2326)

• (1799, 1801)

• (1776, 1823)

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

CCSS.HSS.ID.A.4

The 90% interval for a statistics test was given by 72 +- 7. What is the lower bound for the interval?

• 7
• 72
• 65
• 79

Tags

CCSS.HSS.IC.B.4

A 90% confidence interval for the mean speed driven by cars on East Main St. is given by (21, 45). What was the sample mean of this study?

• 12
• 24
• 33
• None of these.

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

A 90% confidence interval for the mean speed driven by cars on East Main St. is given by (21, 45). What was the margin of error of this study?

• 12
• 24
• 33
• None of these.

Tags

CCSS.HSS.IC.B.4

The amount added and subtracted to the statistic.

• Margin of Error

• Point Estimator

• Statistic

• Population

Tags

CCSS.HSS.IC.B.4

A 90% confidence interval for the average salary of all CEOs in the electronics industry was constructed using the results of a random survey of 45 CEOs. The interval was ($139,048, $154,144). What is another way to write this interval?

• 146,596 ± 7,548

• 154,144 ± 15,096

• 146,596 ± 15,096

• 15,096 ± 7,548

Thirty randomly selected students took the calculus final. If the sample mean was 92 and the standard deviation was 9.4, find the standard error of the sample mean.

• 16.8

• 3.06

• 1.72

• 0.10

What does n = 51 indicate?

• There are 51 data values included in the sample.

• There are 51 data values in the population.

• The mean of the sample is 51.

• In order to achieve 95% confidence, 51 subjects must be included in the study.