Given, we have the report representing children spending time online, on social media or watching T.V, which has there effect on there grades as above or below 80.

By the question we know that the number of students who spends less than 4 hours a week on screen is:

9 + 9

= 18

And among the 18 students there are 9 students whose grade average is below 80.

So the percentage of the students who spends 4 hours a week on screen is:

= 9 ÷ 18 × 100%

= 100/2

= 50%

hence 50% students spend less than 4 hours a week on screens.

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3 0

1 year ago

Answer number 1 please.

Minchanka [31]

$\sf {a}^{2} = {13}^{2} - {5}^{2}$

Formula :

Base²= Hypotenuse² - Perpendicular ²

$\\ \\$

$\hookrightarrow\sf {a}^{2} = {13}^{2} - {5}^{2}$

$\\ \\$

$\hookrightarrow\sf {a}^{2} =169 - 25$

$\\ \\$

$\hookrightarrow\sf {a}^{2} =144$

$\\ \\$

$\hookrightarrow\sf {a} = \sqrt{144}$

$\\ \\$

$\hookrightarrow\sf {a} = \sqrt{12 \times 12}$

$\\ \\$

$\hookrightarrow\sf {a} = 12$

Remember the a² in formula has nothing to do with the a we have to find. :)

6 0

3 years ago

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