Question

a random sample of students were surveyed as to how much non - school screen time they had each week (for purposes of the survey, screen time was defined as: time spent online, on social media, watching tv, or playing video games) and if their grade average was above or below 80.
screen time

	above	below
4 - 8 hours	20	14
8 - 12 hours	19	10
more than 12 hours	12	15

what percent of the students who spend less than 4 hours a week on screens reported a grade average above 80? round your answer to the nearest tenth of a percent.

Explanation:

Step1: Identify relevant numbers

From the table, for "less than 4 hours" screen time: number with grade above 80 is 7, total in this category is \(7 + 10 = 17\).

Step2: Calculate percentage

Percentage = \(\frac{\text{above 80}}{\text{total in category}} \times 100=\frac{7}{17} \times 100\)
Calculate \(\frac{7}{17}\approx0.41176\), then \(0.41176\times 100 = 41.176\%\)

Step3: Round to nearest tenth

\(41.176\%\) rounded to nearest tenth is \(41.2\%\)

Answer:

\(41.2\%\)