A principal randomly chose 40 students from grade 5.Of these students,9 were wearing watches.Based on this information, what is the most reasonable prediction of the number of students wearing watches Ina group of 120 students from grade 5????
A.27
B. 9
C.18
D.80
Please help I'll give a medal !!!

Question

A principal randomly chose 40 students from grade 5.Of these students,9 were wearing watches.Based on this information, what is the most reasonable prediction of the number of students wearing watches Ina group of 120 students from grade 5????
A.27
B. 9
C.18
D.80
Please help I'll give a medal !!!

amistre64 · Answer

and your thoughts about it?

amistre64 · Answer

how do we solve a proportion?

amistre64 · Answer

9 out of 40 is proportionate to x out of 120

9/40 = x/120, solve for x

anonymous · Answer

..????

studygurl14 · Answer

@Valerie_diaz123 
You will need to cross-multiply. Do you know how to do that?

anonymous · Answer

U just do that ?? Yes I do know how to do that

studygurl14 · Answer

Yes, do that. And then finish solving for x.

studygurl14 · Answer

The equation that @amistre64 gave was 
$\Large\frac{9}{40}=\frac{x}{120}$

anonymous · Answer

Thanks and the answer that I got was A