Chapter 7.4, Problem 55PPE

a.

To determine

To write: During one year, people in the United States older than 18 years old watched a total of 342 billion hours of television. The population of the United States older than 18 years old was about 209 million people. On average, how many hours of television did each person older than 18 years old watch that year?

Answer to Problem 55PPE

The required answer is: each person watched 1636.36 hours of television that year

Explanation of Solution

Given information:

The given information: 209 million people watch 342 billion hours of television

Calculation:

209 million people $=209000000$

  $=2.09\times {10}^8$

(Scientific notation)

342 billion hour $=342000000000$

  $=3.42\times {10}^{11}$

(Scientific notation)

  $\frac{3.42\times {10}^{11}}{2.09\times {10}^8}=\frac{3.42}{2.09}\times {10}^{11-8}$

(Subtract exponents when dividing powers with the same base)

  $\begin{array}{l}=\frac{3.42}{2.09}\times {10}^3\\ =\frac{3.42}{2.09}\times 1000\\ =1.63636\times 1000\\ =1636.36\end{array}$

(Simplify)

Therefore on average, each person older than 18 years old watched 1636.36 hours of television that year.

b.

To determine

To write: During one year, people in the United States older than 18 years old watched a total of 342 billion hours of television. The population of the United States older than 18 years old was about 209 million people. On average, how many hours per week did each person older than 18 years old watch that year?

Answer to Problem 55PPE

The required answer is: each person watched 31.47 hours per week that year

Explanation of Solution

Given information:

The given information: 209 million people watch 342 billion hours of television

Calculation:

Each person watched 1636.36 hours of television in a year

Average hours per week $=\frac{1636.36}{52}$

(Divide by number of weeks in a year which is 52)

  $=31.47$

(Simplify)

Therefore on average, each person older than 18 years old watched 31.47 hours of television per week that year.