State whether the relationship between the variables in the table is a direct variation, an inverse variation, or neither. if it is a direct or inverse variation, write a function to model it.
x=3,9,13,20
y=9,27,39,60

Direct variation says that:

then the equation is of the form: y = kx .....[1] where k is the constant of variation.

From the given tables:

Consider any values of x and y:

x = 3 and y = 9

then;

Substitute these in [1] we get;

Divide both sides by 3 we get;

⇒

Check:

Let x = 1 and y = 39

substitute in the equation: y =3k

39 = 3(13)

39 = 39  True

Therefore, the relationship between the variables in the table is a direct variation and the function that represents the model is, y = 3x

the monthly balance will be $75,000