Question

Of the 50 students in the cafeteria, 7 have red hair. Suppose there are 750 students in the school. Write a proportion that could be used to predict the number of students who have red hair. Use x to represent the number of students who have red hair.

Answer 1

Given:

Of the 50 students in the cafeteria, 7 have red hair.

Total number of students = 750

To find:

The proportion that could be used to predict the number of students who have red hair.

Solution:

Let x represent the number of students who have red hair.

The ratio of student having red hair to the total number of students are

`Ratio_1=(7)/(50)`

`Ratio_2=(x)/(750)`

The number of students having red hair is proportional to the total number of students. So, the above ratios are equal.

`(x)/(750)=(7)/(50)`

Multiply both sides by 750.

`(x)/(750)* 750=(7)/(50)* 750`

`x=7* 15`

`x=105`

Therefore, the required equation is
`(x)/(750)=(7)/(50)` and the number of students who have red hair is 105.