Element X is a radioactive isotope such that its mass decreases by 73% every hour. If an experiment starts out with 680 grams of Element X, write a function to represent
the mass of the sample after t hours, where the rate of change per minute can be
found from a constant in the function. Round all coefficients in the function to four
decimal places. Also, determine the percentage rate of change per minute, to the
nearest hundredth of a percent.