Find a constant of proportionality that creates a direct proportion to x and y

Please check the explanation.

Step-by-step explanation:

We know that when 'y' varies directly with 'x', we get the equation

y ∝ x

y = kx

k = y/x

Here k is called the constant of proportionality.

Taking an example:

For example, let suppose x and y are directly proportional with x = 4 and y = 10.

We can calculate the constant of proportionality using the formula

k = y/x

substitute x = 4, y = 10 in the equation

k = 10/4

k = 2.5

And at x = 5 and y = 12.5

k = y/x

substitute x = 5, y = 12.5 in the equation

k = 12.5/5

k = 2.5

Therefore, we conclude that a constant of proportionality k = 2.5.

a. the are of the rectangle is 18.25

b. 18.25 times two is 36.50

rae me : d