In a classroom, 5 out of 13 students surveyed said they had two or more siblings. If the entire school has 520 students, predict the number of students that have two or more siblings. Write a proportion to model the problem.

Question

johnweldon1993 · Answer

Well we can write the proportion as

$$\large \frac{5}{13} = \frac{x}{520}$$

johnweldon1993 · Answer

Then to solve it...you would cross multiply

$$\large 2600 = 13x$$
And then you would divide both sides by 13 to solve for 'x'

$$\large x = \frac{2600}{13} = \space ? $$

anonymous · Answer

thanks i have one more....  In a classroom, 11 out of 17 students surveyed say they had two or more siblings. If the entire school has 850 students, predict the number of students that have two or more siblings.

johnweldon1993 · Answer

So same thing there...

$$\large \frac{11}{17} = \frac{x}{850}$$
$$\large 9350 = 17x$$
$$\large x = \frac{9350}{17} = \space ? $$

anonymous · Answer

oh.. ok thanks.. i thought so!!! i am just checking my answers

johnweldon1993 · Answer

No problem :)