Answer
A.
$P(Excellent~|~A)\gt P(Excellent~|~B)\gt P(Excellent~|~C)$.
Work Step by Step
$N(A)=1+8+21=30$.
$N(B)=0+11+19=30$.
$N(C)=6+11+13=30$.
$N(Excellent~and~A)=23$.
$N(Excellent~and~B)=19$.
$N(Excellent~and~C)=13$.
Using the Conditional Rule (page 288):
$P(Excellent~|~A)=\frac{N(Excellent~and~A)}{N(A)}=\frac{23}{30}$
$P(Excellent~|~B)=\frac{N(Excellent~and~B)}{N(B)}=\frac{19}{30}$
$P(Excellent~|~C)=\frac{N(Excellent~and~C)}{N(C)}=\frac{13}{30}$
$P(Excellent~|~A)\gt P(Excellent~|~B)\gt P(Excellent~|~C)$.
