Mac	PC	Total
Greek	No	293	155	448
Yes	168	25	193
	Total	461	180	641

What proportion of Greek students own a Mac? This is called a conditional probability because we are calculating the probability of a student owning a Mac conditional upon knowing the student is Greek. The appropriate notation for this probability is P(M|G) and is read "the probability of selecting a student that owns a Mac given the selected student is in a Greek organization."

Find this probability by restricting your attention to only the row for Greek students and determining what proportion own a Mac.