Question

Find the constant of proportionality for the table of values.

x 2 3 4 5
y 3 4.5 6 7.5


The constant of proportionality is k =

Answer 1

k = 1.5

Explanation:

Pairs: (2, 3), (3, 4.5), (4, 6), (5, 7.5)

If there is a proportionality between two numbers or, as in this case, two variables, then:

y = kx

Where:

k = proportionality constant

The constant can therefore be found by rearranging:

k = y/x

Now, simply substitute any given pair of x- and y- values;

I will use (2, 3) as these are the smallest numbers so easier to use but any of the pairs can be used:

k = 3/2

k = 1.5