Question

Which table has a constant of proportionality between Y and X of 1.5?
Choose one answer.

Answer 1

Table C

Explanation:

The variable x is directly proportional to y according to table

C because each of the variable x keeps increasing by the same factor which is 1.5. This factor is known as their constant of proportionality

If y is directly proportional to x, it is expressed as x ∝ y

x = ky where k is the constant of proportionality

When x1 = 8, y1 = 12

When x2 = 9, y2 = 13.5

When x3 = 18, y2 = 27

Since k = y/x

k = y1/x1 = y2/x2 = y3/x3

k = 12/8 = 13.5/9 = 27/18 = 1.5

This shows that they all have the same constant of proportionality which is 1.5