In pharmacologic research a variety of clinical chemistry
measurements are routinely monitored closely for evidence
of side effects of the medication under study. Suppose
typical blood-glucose levels are normally distributed, with
mean = 90 mg/dL and standard deviation = 38 mg/dL.
5.31 If the normal range is 65−120 mg/dL, then what percentage
of values will fall in the normal range?
5.32 In some studies only values at least 1.5 times as high
as the upper limit of normal are identified as abnormal. What
percentage of values would fall in this range?
5.33 Answer Problem 5.32 for values 2.0 times the upper
limit of normal.
5.34 Frequently, tests that yield abnormal results are repeated
for confirmation. What is the probability that for a
normal person a test will be at least 1.5 times as high as the
upper limit of normal on two separate occasions?
5.35 Suppose that in a pharmacologic study involving 6000
patients, 75 patients have blood-glucose levels at least 1.5
times the upper limit of normal on one occasion. What is the
probability that this result could be due to chance?