Question

This graph models the number of teachers assigned to a school, as determined by the number of students. What is the constant of proportionality?

1/25
1/20
1/15
1/10

Answer 1

(60,4)(120,8)
slope = (8 - 4) / (120 - 60) = 4/60 = 1/15 <== the constant of proportionality is the slope

Answer 2

The correct option is 3.

Explanation:

Form the given figure it is noticed that the line is passing through the points (60,4) and (120,8).

`y\propto x`

`y=kx`

Where, k is the constant of proportionality or slope.

The slope of a line is defined as

`k=(y_2-y_1)/(x_2-x_1)`

`k=(8-4)/(120-60)`

`k=(4)/(60)`

`k=(1)/(15)`

Therefore option 3 is correct.