Answer
$P(Mallory~|~Single-Cup)=\frac{3}{25}=0.12$
Work Step by Step
The sample space: 1009 cases. So, $N(S)=1009$
According to the marginal distribution (see page 235) of the second column: $N(Single-Cup)=625$
According to the cell in the fourth row, second column: $N(Mallory~and~Single-Cup)=75$
Using the Conditional Probability Rule (page 288):
$P(Mallory~|~Single-Cup)=\frac{N(Mallory~and~Single-Cup)}{N(Single-Cup)}=\frac{75}{625}=\frac{3}{25}=0.12$
