(a) Estimate the number of times your heart beats in 1 year. Express your answer in scientific notation. 

(b) Some people have (jokingly) suggested that each person has only a certain number of heartbeats before he or she dies. The average life expectancy for a person born in the United States in 2004 is 77.9 years. If the average person’s heart rate were reduced by 12%, how long would he or she live? Be sure to give the correct number of significant figures in your answer.