On average, a person's heart beats about 4.2 x 10 to the power of 7 times per year. There are about 7,600,000,000 people in the world. Use this data to determine the approximate number of heartbeats for all people in the world per year. Expressing your answer in scientific notation in the or a x 10^b, what are the values of a and b?

The boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a) e = 2b - 212 b) b = 2e - 212 c) e = -2b + 212 d) b = -2e + 212