Credit card ownership varies across age groups. Suppose that the estimated percentage of people who own at least one credit card is 64% in the 18–24 age group, 84% in the 25–34 age group, 75% in the 35–49 age group, and 77% in the 50+ age group. Suppose these estimates are based on 465 randomly selected people from each age group. (a) Construct a 95% confidence interval for the proportion of people in the 18–24 age group who own at least one credit card. (Round your answers to four decimal places.) to Construct a 95% confidence interval for the proportion of people in the 25–34 age group who own at least one credit card. (Round your answers to four decimal places.) to Construct a 95% confidence interval for the proportion of people in the 35–49 age group who own at least one credit card. (Round your answers to four decimal places.) to Construct a 95% confidence interval for the proportion of people in the 50+ age group who own at least one credit card. (Round your answers to four decimal places.) to (b) Assuming the same sample size will be used in each age group, how large would the sample need to be to ensure that the margin of error is 0.03 or less for each of the four confidence intervals? (Round your answer up to the nearest integer.)
Credit card ownership varies across age groups. Suppose that the estimated percentage of people who own at least one credit card is 64% in the 18–24 age group, 84% in the 25–34 age group, 75% in the 35–49 age group, and 77% in the 50+ age group. Suppose these estimates are based on 465 randomly selected people from each age group.
(a)
Construct a 95% confidence interval for the proportion of people in the 18–24 age group who own at least one credit card. (Round your answers to four decimal places.)
to
Construct a 95% confidence interval for the proportion of people in the 25–34 age group who own at least one credit card. (Round your answers to four decimal places.)
to
Construct a 95% confidence interval for the proportion of people in the 35–49 age group who own at least one credit card. (Round your answers to four decimal places.)
to
Construct a 95% confidence interval for the proportion of people in the 50+ age group who own at least one credit card. (Round your answers to four decimal places.)
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(b)
Assuming the same sample size will be used in each age group, how large would the sample need to be to ensure that the margin of error is 0.03 or less for each of the four confidence intervals? (Round your answer up to the nearest integer.)
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