Final answer:
The statement that is NOT true about odds ratios is that they represent the probability of success over the probability of failure. Odds ratios are actually calculated by comparing the odds between two groups, not by stating probabilities.
Step-by-step explanation:
The correct answer to the question which statement is NOT true about odds ratios is: a. The odds ratio is the probability of success over the probability of failure. This statement is not accurate because the odds ratio is actually a measure of association between two conditions, not simply a probability.
Odds ratios are calculated by taking the odds of an event occurring in one group and dividing it by the odds of it occurring in another group. Essentially, it compares the odds of a certain event happening between two different groups. The odds being referred to here is the ratio of the probability of success to the probability of failure (p/q), not the probabilities themselves.
Additionally, statement d is partly misleading. While a decrease in the odds ratio often suggests a decreased probability of success in relation to failure, it does not directly translate to probabilities since odds and probabilities are different metrics.
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