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posted by dic .
In the tests of a new pharmaceutical product, data were collected for use in the approval process required by the U.S. Food and Drug Administration (FDA). Some participants were given a placebo, an inert substance that looks like the drug; others were given the drug. The data are shown in the following table:
No Help Help
Drug 22 47
Placebo 31 20
What is the probability that
a. the participants perceived that their “medication” helped if they received the drug?
b. the participants perceived that their “medication” helped if they received the placebo?
c. the participants perceived that their “medication” helped?

total number that got drug = 22+47 = 69
total number that got placebo = 31+20 =51
total number not helped =22+31 = 53
total number helped = 67
total number of people = 120 in study
a) 47/69
b) 20/51
c) 67/120