In a random sample of 765 adults in the United States, 322 say they could not...

In a random sample of 765 adults in the United States, 322 say they could not cover a $400 unexpected expense without borrowing money or going into debt.

A.)Find the mean and the standard deviation of p-hat for this sample

B.) Given the sample data in problem (1) above, construct a confidence interval at the 95% confidence level for the true proportion of Americans who could not cover a $400 unexpected expense without borrowing money or going into debt.

C.)4) Finding confidence intervals stems from getting a normal distribution of a sample proportion p-hat. If I estimate my population proportion to be no greater than 95%, what is the smallest sample size I can use to ensure I have a large enough sample to make a confidence interval?

Please help

Expert Solution

orchestra answered 2 years ago

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