From a random sample of 1201 americans, it was discovered that 1139

From a random sample of 1201 Americans, it was discovered that 1139 of them lived in neighborhoods with acceptable levels of carbon monoxide.

A) Obtain a point estimate for the proportion of Americans who live in neighborhoods with acceptable levels of carbon monoxide.
B) Construct a 99% confidence interval for the proportion of Americans who live in neighborhoods with acceptable levels of carbon monoxide.
C) You wish to conduct your own study to determine the proportion of Americans who live in neighborhoods with acceptable levels of carbon monoxide. What sample size would be needed for the estimate to be within 1.5 percentage points with 90% confidence if you use the estimate obtained in part (a)?
D) You wish to conduct your own study to determine the proportion of Americans who live in neighborhoods with acceptable levels of carbon monoxide. What sample size would be needed for the estimate to be within 1.5 percentage points with 90% confidence if you do not have a prior estimate?
2.) Travelers pay taxes for flying, car rentals, and hotels. The following data represents the total travel tax for a 3-day business trip in eight randomly selected cities. Note: Chicago has the highest travel taxes in the country at $101.27. Data is normally distributed and s= 12.324 dollars. Construct and interpret a 90% confidence interval for the standard deviation travel tax for a 3-day business trip.

67.81 78.69 68.99 84.36
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80.24 86.14 101.27 99.29