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 aver-aged 0.3 hour (18 minutes) per day using a computer for leisure. Individuals ages 15 to 19 spend 1.0 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 15 minutes per day using a computer for leisure.
b. More than 2 hours.
c. Between 30 minutes and 90 minutes using a computer for leisure.
d. Find the 20th percentile. Eighty percent spend more than what amount of time?