A sample of 30 newly minted quarters was taken and it was found that the average
ID: 3154993 • Letter: A
Question
A sample of 30 newly minted quarters was taken and it was found that the average weight was 5.625 g with a standard deviation of 0.028 g. Based on this random sample, construct a 95% confidence interval estimate of the population MEAN weight of newly minted quarters. Assume that the population standard deviation is unknown. What is the critical T value? What is the confidence interval? The U.S. Department of Treasury claims that it mints quarters to yield a mean weight of 5.60 g. Is this claim consistent with the confidence interval you just calculated? Explain your conclusion and account for any possible discrepancies.
Explanation / Answer
alpha / 2 = 0.025 df=29 critical value T = 2.045
I: 5.625 +/- 2.045 * 0.028 / srqt 30
5.625 +/- 0.01045
5.61455 < miu < 5.62545
Department of Treasury claims that it mints quarters to yield a mean weight of 5.60 g. Is this claim consistent with the confidence interval you just calculated?
the claim si not consistent with confidence interval because 5.60 is not included in the interval