Statistics Ch. 7 EC Quiz

Fill in the blank to complete the statement: “For a specific confidence interval, the smaller the sample size, the ____ the margin of error will be.”

• Smaller

• Larger

Tags

CCSS.HSS.IC.B.4

Suppose that the 95% confidence interval for a population mean is 15 < u < 18. Which of the following is the proper way to interpret this confidence interval?

• 95% of the time this interval will contain the population mean.

• 95% of all sample means will be in this interval.

• The top 95% of the sample means will be in this interval.

• The population mean is somewhere between 15 and 18.

Tags

CCSS.HSS.IC.B.4

The best point estimate of the population mean is

• The mean

• The median

• The mode

• The midrange

Suppose you calculate a 94% confidence interval instead of a 90% confidence interval, and you keep the sample size n the same. How will the margin of error be affected?

• Cannot be determined.

• The margin of error will decrease.

• The margin of error will increase.

• The margin of error will remain the same.

Tags

CCSS.HSS.IC.B.4

Calculate the critical z value for a 76% confidence level.

• 0.71

• 0.24

• 1.31

• 1.18

Tags

CCSS.HSS.ID.A.4

In a study of 1200 randomly selected cancer patients, 91% reported no family history of cancer. What is the 90% confidence interval of the true proportion of cancer patients with no family history of cancer?

• 0.892 < p < 0.928

• 0.896 < p < 0.924

• 0.887 < p < 0.933

• 0.901 < p < 0.919

Tags

CCSS.HSS.IC.B.4

What should be the sample size of a study if the true proportion of sports fans are to be determined within 2%, with a 98% confidence level? A previous study found that 72% of 58 people surveyed are sports fans.

• 202

• 485

• 2737

• 3355