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 0.15 hour (9 minutes) per day using a computer for leisure. Individuals ages 15 to 19 spend 0.9 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 9 minutes per day using a computer for leisure

Answer 1

The probability that a computer is used for entertainment between 1.8 and 2.75 hours per day is 58.86%. To determine the maximum hours used daily by the bottom quartile for entertainment requires more information on the distribution. When testing for increased average phone usage by teenagers, null and alternative hypotheses are established for comparison.

Step-by-step explanation:

The probability that a household personal computer is used for entertainment between 1.8 and 2.75 hours per day can be found using the cumulative distribution function (CDF) of the normal distribution, given that the average time is 2 hours with an assumed standard deviation.

The calculation for this probability has been done using the normalcdf function, which provides the result as 0.5886.

This means there is a 58.86% chance that a computer is used between these hours for entertainment.

To find the maximum number of hours per day that the bottom quartile (25th percentile) of households uses a personal computer for entertainment, you would need to find the value of k where P(x < k) = 0.25 in the appropriate distribution.

However, to perform this calculation, additional information about the distribution is needed.