The dwarves of the Grey Mountains wish to conduct a survey of their pick-axes in order to construct a 99% confidence interval about the proportion of pick-axes in need of repair. What minimum sample size would be necessary in order ensure a margin of error of 10 percentage points (or less) if they use the prior estimate that 25 percent of the pick-axes are in need of repair?

The minimum sample size needed is 125.

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 zscore that has a pvalue of .

The margin of error is:

For this problem, we have that:

99% confidence level

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

What minimum sample size would be necessary in order ensure a margin of error of 10 percentage points (or less) if they use the prior estimate that 25 percent of the pick-axes are in need of repair?

This minimum sample size is n.

n is found when

So

Rounding up

The minimum sample size needed is 125.

savings account is an account only used for saving money. this acts as an emergency source of funding for an individual. answer a would result in the money in his account to grow as it specifically states that interest is compounded daily at the rate of 2%

step-by-step explanation:

answer: i could not see part the question so ill explain how to get the answer

step-by-step explanation: for instance the distance she travele d is 10 and she traveled the same amout each mile so do 10 divided by how many miles she drove each time and you ge your answer.