A clinical hypothesis arising from DB9 might be: The standard deviation of platelet counts is 60,000 which gives an approximate 95% confidence range of 240,000 [mean +2 • 60,000]); this hypothesis is equivalent to supposing that the variance is 60,0002 - 3,600,000,000.

(a) What probability distribution is associated with this hypothesis?

(b) What assumptions about the data would be required to investigate this hypothesis?

(c) State in words the Type I and Type II errors associated with this hypothesis.

(d) How would the probability (risk) of these errors be designated?