Question

Select the correct answer from each drop-down menu.
Enrollment at Roosevelt Middle School is being reviewed by the school staff. The table gives the numbers of boys and girls in grades 6 to 9.

Grade Girls Boys
6 9 12
7 12 18
8 15 20
9 25 36

In which two grades is the relationship between the numbers of girls and boys proportional?

The two grades that have a proportional relationship between the numbers of girls and boys are
and
.

Answer 1

Answer:

Grades 6 and 8

Step-by-step explanation:

If the relationship of girls to boys in two different grades are proportional, they must have the same ratio. To tackle this problem, we can find the ratios of genders in each grade and compare them.

Step 1, finding ratios:

Finding ratios is just like simplifying fractions. We will reduce the numbers by their greatest common factors.

• GRADE 6:

$9:12=\\3:4$

• GRADE 7:

$12:18=\\2:3$

• GRADE 8:

$15:20=\\3:4$

• GRADE 9:

$25:36$

Can't be simplified!

Step 2:

Notice how grades 6 and 8 both had a ratio of 3:4. We can conclude that these two grades have a proportional relationship between girls and boys.

I hope this helps! Let me know if you have any questions :)