&gt; if the drug is not effective (at all), there is 27.9% probability that the drug would be approved by FDA.<p>Which is only one of two possibilities, and hence, it cannot be &#x27;the probability the drug is approved by the FDA&#x27;, for the same reason that &#x27;a p-value of 0.05&#x27; does not mean &#x27;95% probability the drug works&#x27;.