The Bureau of Labor Statistics' American Time Use Survey showed that the amount of time spent using a computer for leisure varied greatly by age. Individuals age 75 and over averaged .25 hour (15 minutes) per day using a computer for leisure. Individuals ages 15 to 19 spend .9 hour per day using a computer for leisure. If these times follow an exponential distribution, find the proportion of each group that spends:
(a) Less than 14 minutes per day using a computer for leisure. (Round your answers to 4 decimal places
(b) More than two hours
(c) Between 28 minutes and 84 minutes using a computer for leisure
(d) Find the 25th percentile. Seventy five percent spend more than what amount of time? (Round your answers to 2 decimal places.)