Question

finding percent decrease in a real - world problem
every year, a teacher surveys his students about the number of hours a week they watch television. in 2002, his students watched an average of 12 hours of television per week. in 2012, the number of hours spent watching television decreased to five per week.
what is the percent decrease in the hours of television watched, rounded to the nearest tenth?
○ 5.8%
○ 4.2%
○ 41.7%
○ 58.3%

Explanation:

Step1: Find the decrease in hours

The original hours (2002) is 12, and the new hours (2012) is 5. The decrease is \( 12 - 5 = 7 \) hours.

Step2: Calculate percent decrease

The formula for percent decrease is \( \frac{\text{Decrease}}{\text{Original Amount}} \times 100\% \). Substituting the values, we get \( \frac{7}{12} \times 100\% \).
Calculating \( \frac{7}{12} \approx 0.5833 \), then multiplying by 100% gives \( 0.5833 \times 100\% = 58.33\% \), rounded to the nearest tenth is 58.3%.

Answer:

58.3%