Of 2, 500 people who survived a first heart attack, those who did not smoke had their first heart attack at a median age of 62  However, of those 2, 500, people who smoked two packs of cigarettes a day had their first heart attack at a median age of 51
On the basis of this information, it can be concluded that nonsmokers tend to have a first heart attack eleven years later than do people who smoke two packs of cigarettes a day
the relative severity of heart attacks suffered by smokers and nonsmokers