Unit 7 Test Confidence Intervals

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.

A 90% confidence interval for a population mean is determined to be 800 to 900. If the confidence is increased to 95% confidence while the sample statistics and sample size remain the same, the confidence interval

• becomes wider
• becomes narrower
• does not change

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

• Sample mean
• t-score
• Sample standard deviation
• Sample size

When performing a test about the population proportion, what distribution would you need to use? 

• z
• t
• chi-square
• n

These symbols represent the mean and standard deviation for which of the following distributions?

• The Population
• The Sample
• The Sampling Distribution
• The Mean Distribution

Which of the following is NOT a parameter?

• μ
• σ
• p̂
• p

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

• 7
• 72
• 65
• 79

Given the same mean, SD, and sample size, a confidence interval of 80% would be wider than a confidence interval of 90%

• True
• False

If 1757 represents "yes" voters out of 2584, construct a 95% confidence interval for the "yes" group.

• [.670,.710]
• [.658,.702]
• [.662,.698]
• [.648,.712]

The 99% confidence interval for a proportion is (0.54, 0.72). What is p̂?

• 0.63
• 0.18
• 0.09
• 0.66

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4