Asimple random sample of 60 adults is obtained from a normally distributed population, and each person's red blood cell count (in cells per microliter) is measured. the sample mean is 5.25 and the sample standard deviation is 0.55. use a 0.05 significance level and the given calculator display to test the claim that the sample is from a population with a mean less than 5.4 comma which is a value often used for the upper limit of the range of normal values. what do the results suggest about the sample group?