A sample of 40 quarters was taken and it was found that the average weight was 5.522 g with a standard deviation of 0.078 g. Based on this random sample, construct a 95% confidnece interval estimate of the population MEAN of all quarters in circulation.(Assume that the population standard deviation is unknown.) Round your final calculation to three decimal places. What is the critical T value? What is the confidence interval?
The U.S. Dept of Treasury claims that it mints quarters to yield a mean weight of 5.670 g. Is this claim consistent with the convidence interval you just calculated? Explain your conclusion and account for any possible discrepancies. Conclusion: