Question

3. A typical healthy human adult has a mean corpuscular volume (MCV; the average volume of a red blood cell) of around 90 fl (femtolitres, or 10−15 litres). Having an unusually large or small MCV is a sign of various health difficulties. A particular chemotherapy drug is believed to cause a change in MCV levels. A sample of 88 patients had a mean MCV of 92 fl. Assume a population standard deviation of 8.3 fl.

(a) Construct a 95% confidence interval for the population mean MCV, µ

(b) A researcher wishes to test the claim that there is a change in MCV among patients who have been prescribed this drug.

i. Is this a one-tailed or two-tailed test? Why?

ii. Carry out a hypothesis test at the level of significanceα= 0.05.

Answer 1