A Gallup survey of 2322 adults (at least 18 years old) in the U. S. found that 408 of them have donated blood in the past two years. Construct a 90% confidence interval for the population proportion of adults in the U. S. who have donated blood in the past two years.

The 90% confidence interval for the population proportion of adults in the U.S. who have donated blood in the past two years is (0.1627, 0.1887).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.

In which

z is the z-score that has a p-value of .

A Gallup survey of 2322 adults (at least 18 years old) in the U.S. found that 408 of them have donated blood in the past two years.

This means that

90% confidence level

So , z is the value of Z that has a p-value of , so .  

The lower limit of this interval is:

The upper limit of this interval is:

The 90% confidence interval for the population proportion of adults in the U.S. who have donated blood in the past two years is (0.1627, 0.1887).

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step-by-step explanation:

answer: 486in^2

step-by-step explanation: