Question

In math class, 4 students complete individual surveys to determine the percentage of high school teachers that have a second job. Which two surveys show proportional results?
A) A and B

B) B and D

C) A and D

D) B and C

Answer 1

Answer:

Option D) B and C          

Step-by-step explanation:

we know that

To find out the percentage of high school teachers that have a second job, divide the number of teachers that have a second job by the total number of teachers

Survey A

$\frac{28}{110}=0.2545$

Convert to percentage

$0.2545(100)=25.45\%$

Survey B

$\frac{27}{90}=0.3$

Convert to percentage

$0.3(100)=30\%$

Survey C

$\frac{21}{70}=0.3$

Convert to percentage

$0.3(100)=30\%$

Survey D

$\frac{32}{80}=0.4$

Convert to percentage

$0.4(100)=40\%$

Compare the percentages

Surveys B and C have the same percentage

therefore

Surveys B and C show proportional results, because the ratio of the number of teachers that have a second job by the total number of teachers is equal (this number is the constant of proportionality k in a proportional relationship between two variables)