Section 6B Confidence Intervals for a Population Proportion

Multiple Choice

Which of the following is NOT a condition for calculating a confidence interval for a population proportion?

• Random sample from the population of interest

• Sample size less than 10% of the population

• Both np̂ and n(1-p̂) are at least 10

• Sample must be a census

Multiple Select

Which of the following statements about margin of error and critical value is correct?

• Margin of error determines the width of the confidence interval.

• Critical value is used to calculate the standard error.

• Margin of error is always smaller than the critical value.

• Critical value is a multiplier that makes the interval wide enough to have the stated capture rate.

Multiple Choice

What are the four steps in the process of constructing a confidence interval for a population proportion?

• State, Plan, Calculate, Conclude

• State, Plan, Do, Conclude

• State, Calculate, Do, Conclude

• Plan, State, Do, Conclude

Multiple Choice

Which conditions must be checked before constructing a one-sample z interval for a proportion?

• Random sample, 10% condition, Large counts

• Random sample, Small counts, 10% condition

• Random sample, 5% condition, Large counts

• Random sample, 10% condition, Small counts

Multiple Select

Which of the following changes would result in a wider confidence interval for a population proportion?

• Decreasing the confidence level

• Increasing the sample size

• Increasing the confidence level

• Decreasing the sample size

Textbook Problems Pages 556-560 #s 14, 18, 30, & M.C. # 31-37