Regard to the remaining two categories, computer and smartphone both increased sharply throughout the whole period. USA citizen spent about 20 hours per month to used computer, it climbed 18 times between 1980 and 2015. Finally, the rate of smartphone changed dramatically. It stood at 1 hours in 1980, it increased to 350 hours from 1980 to 2015

The provided graph illustrates the number of contemporary technology that people used in USA between 1980 and 2015. Overall, it is clearly seen that radio was the highest rate at the beginning of the period. In addition, American people used more computer as time passes by. Firstly, the proportion of radio was about 320hours per month in 1980, it decreased to below 150 hours in 2005 and keep dropped gradually until just under 100 hours in 2015. However, people who lived in the USA used television only about 49 hours and it climbed to just above to 200 hours during 30-year period. In 2015, people used slightly less than the past which is 199 hours per month. Regard to the remaining two categories, computer and smartphone both increased sharply throughout the whole period. USA citizen spent about 20 hours per month to used computer, it climbed 18 times between 1980 and 2015. Finally, the rate of smartphone changed dramatically. It stood at 1 hours in 1980, it increased to 350 hours from 1980 to 2015