Answer
P(headache went away within 45 minutes) $=\frac{94}{125}=0.752$
Work Step by Step
The sample space: $150+100=250$ women in the study. So, N(S) = 250.
There were a total of $132+56=188$ women whose headache went away within 45 minutes. So, N(headache went away within 45 minutes) = 188.
P(headache went away within 45 minutes) = $\frac{N(\text{headache went away within 45 minutes})}{N(S)}=\frac{188}{250}=\frac{94}{125}=0.752$
