A simple random sample of 55 screws supplied by a certain manufacturer is obtained, and the length of each screw in measured.?The sample mean is found to be 0.459 in. Assume that the standard deviation of all such length is 0.017 in, and use a 0.01 significance level to test the claim that the screws have a mean length equal to ½ in. (or 0.5in), as indicated on the package labels. Do the screw lengths appear to be consistent with the package label?
What are the null and alternative hypotheses?
What us the value of the test statistic?
The P-value is?