Some people who have heart attacks do not experience chest pain, although most do. A study of people admitted to emergency rooms with heart attacks compared the death rates of people who had chest pains with those of people with less typical symptoms. Of the 1763 people who had heart attacks without chest pain, 229 died, while on the 19,118 people who had heart attacks with chest pain, 822 died. Do a chi-square test to determine whether having chest pains during a heart attack is related to probability of death.