Let x be a random variable that represents red blood cell (RBC)count in millions of cells per cubic millimeter of whole blood.Then x has a distribution that is approximately normal. For thepopulation of healthy female adults, the mean of the x distributionis about 4.8 (based on information from Diagnostic Tests withNursing Implications, Springhouse Corporation). Suppose that afemale patient has taken six laboratory blood tests over the pastseveral months and that the RBC count data sent to the patient’sdoctor are 4.9, 4.2, 4.5, 4.1, 4.4, 4.3
(a) Use a calculator to verify that ??= 4.40 and ? = 0.28.
(b) Do the given data indicate that the population mean RBCcount for this patient is lower than 4.8? Use ? = .05.
(c) Obtain a 90% confidence interval for the mean RBC count.
(d) Can you come to the same conclusion you made in (b) usingthe interval approach in (c).
