Question

1.Based on information in Statistical Abstract of the United States (116th edition), the average annual miles driven per vehicle in the United States is 11.1 thousand miles, with sigma of 600 miles. Suppose that a random sample of 36 vehicles owned by residents of Chicago showed that the average mileage driven last year was 10.8 thousand miles. Does this indicate that the average miles driven per vehicle in Chicago is different from (higher or lower than) the national average? Use a 0.05 level of significance. (Hint: use the three steps to perform a hypothesis testing)

.2.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

a.Do the given data indicate that the population mean RBC count for this patient is lower than 4.8? Use sigma 0.05. (Hint: use the three steps to perform a hypothesis testing).

Answer 1