Question

cherry tree middle school has 300 seventh graders. a survey was conducted with 90 randomly selected 7th graders asking about their favorite hobby to engage in during their free time. the results are shown in the table below. answer the questions based on the data given.
favorite hobbies
video games 36
social media 18
creating internet videos 9
movies/tv 20
other 7
5 about how many 7th graders prefer to play video games in their free time?
6 approximately what percent of the population chooses to create internet videos?
7 if those conducting the survey originally predicted that 25% of students would choose movies/tv as their favorite hobby, about how many percentage points off was their prediction? round to the nearest 10th.

Explanation:

Step1: Find sample proportion for video games

$\frac{36}{90} = 0.4$

Step2: Scale to total 7th graders

$0.4 \times 300 = 120$

Step3: Find % for internet videos

$\frac{9}{90} \times 100 = 10\%$

Step4: Calculate actual % for Movies/TV

$\frac{20}{90} \times 100 \approx 22.22\%$

Step5: Find prediction error

$|25\% - 22.22\%| \approx 3\%$

Answer:

1. 120
2. 10%
3. 3 percentage points