Question

Marion Middle School has 600 students. Mike surveys a random sample 7 of 30 students and finds that 7 of them play a musical instrument. How many students at the school are likely to play a musical instrument?

Please explain how as well.

Answer 1

Do a proportion
7/30=x/600
1. Cross multiply
7x600=4200
30•X= 30x
30x=4200
Divide each side with the number with the variable.
30x/30=4200/30
X=140

Answer 2

So if 7/30 students plays an instrument then you'll need to set up an equation for this. The equation you'd use would be:
7/30 = x/600
Then, cross multiply to get:
30x = 4200
Lastly, divide each side by 30 and:
x = 140 students play a musical instrument

Hope this helps!! :)