Government data assign a single cause for each death that occurs in the United States. (Thus, in government terminology, causes of death are mutually exclusive.) In a certain city, the data show that the probability is 0.37 that a randomly chosen death was due to cardiovascular (mainly heart) disease, and 0.25 that it was due to cancer. (a) The probability that a death was due either to cardiovascular disease or to cancer is __________. (b) The probability that the death was not due to either of these two causes is ____________.