Question

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 0.20 hour (12 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: Less than 13 minutes per day using a computer for leisure. (Round your answers to 4 decimal places.) More than 2 hours. (Round your answers to 4 decimal places.) Between 26 minutes and 78 minutes using a computer for leisure. (Round your answers to 4 decimal places.) Find the 32th percentile. Sixty-eight percent spend more than what amount of time? (Round your answers to 2 decimal places.)

Answer 1

a)

age 75 and over :P(Less than 13 minutes)=1-exp(-13/12)=0.6615

ages 15 to 19 spend :P(Less than 13 minutes)=1-exp(-13/60)=0.1948

b)

age 75 and over :P(More than 2 hours)=exp(-120/12)=0.0000

ages 15 to 19 spend :P(More than 2 hours)=exp(-120/60)=0.1353

c)

age 75 and over :P(Between 26 minutes and 78 minutes)=0.1131

ages 15 to 19 spend :P(Between 26 minutes and 78 minutes)=0.3758

d)

age 75 and over :32th percentile=4.63

ages 15 to 19 spend :32th percentile=23.14 minute