Medical: Red Blood Cell Count 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 the population of healthy female adults, the mean of the x distribution is about 4.8 (based on information from Diagnostic Tests with Nursing Implications, Springhouse Corporation). Suppose that a female patient has taken six laboratory blood tests over the past several months and that the RBC count data sent to the patient’s doctor are 4.9 4.2 4.5 4.1 4.4 4.3 i. Use a calculator with sample mean and sample standard deviation keys to verify that x 5 4.40 and s < 0.28.

ii. Do the given data indicate that the population mean RBC count for this patient is lower than 4.8? Use a 5 0.05.