During a recent drought, a water utility in a certain town sampled 100 residential water bills and found that 73.0 of the residences had reduced their water consumption over that of the previous year. a) Find a 95% confidence interval for the proportion of residences that reduced their water consumption. (Round the final answers to three decimal places.) b) Find a 99% confidence interval for the proportion of residences that reduced their water consumption. (Round the final answers to three decimal places.) c) Find the sample size needed for a 95% confidence interval to specify the proportion to within ±0.04. (Round the final answer to the nearest whole number.) d) Find the sample size needed for a 99% confidence interval to specify the proportion to within ±0.04. (Round the final answer to the nearest whole number.)
During a recent drought, a water utility in a certain town sampled 100 residential water bills and found that 73.0 of the residences had reduced their water consumption over that of the previous year.
a) Find a 95% confidence interval for the proportion of residences that reduced their water consumption. (Round the final answers to three decimal places.)
b) Find a 99% confidence interval for the proportion of residences that reduced their water consumption. (Round the final answers to three decimal places.)
c) Find the
d) Find the sample size needed for a 99% confidence interval to specify the proportion to within ±0.04. (Round the final answer to the nearest whole number.)
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