Aresearcher wishes to see whether the variances of the process (in seconds) on machine a are different from the variances of process (in seconds) on machines other than machine a. the researcher selects two samples, and the data are below. using a = 0.05, the researcher tests to see if enough evidence exists to support the claim. for machine a, n1 = 16 and = 18. for machines other than machine a, n2 = 18 and = 16. what is the test value f