Concept explainers
Testing a Drug. A new cold medication was tested by giving 100 people the drug and loo people a placebo. A control group consisted of 100 people who were given no treatment. The number of people in each group who showed improvement is shown in the table below.
Cold drug | Placebo | Control | Total | |
Improvement | 70 | 55 | 20 | 145 |
No improvement | 30 | 45 | 80 | 155 |
Total | 100 | 100 | 100 | 300 |
a. What is the probability that a randomly selected person in the study either was given the placebo or was in the control group?
b. What is the probability that a randomly selected person improved?
c. What is the probability that a randomly selected person was given the drug and improved?
d. What is the probability that a randomly selected person who improved was given the drug?
e. What is the probability that a randomly selected person who was given the drug improved?
f. Based on these data, does the drug appear to be effective? Explain.
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Using & Understanding Mathematics: A Quantitative Reasoning Approach (7th Edition)
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