the graph should be discrete, even though often times you will see it graphed as continuous only because the graphing software used might not have the capability of showing discrete dots rather than continuous lines. Basically you can only sell whole tickets , so that makes the value of x integers .
the fact that y is not an integer is irrelevant.
in fact, y is also restricted in the values it can take.
those values are determined by the factor of 2.50 * x.
when x = 0, y = 0 * 2.50 = 0
when x = 1, y = 1 * 2.50 = 2.50
when x = 2, y = 2 * 2.50 = 5.00
when x = 3, y = 3 * 2.50 = 7.50
when x = 4, y = 4 * 2.50 = 9.00
the values of y can only be multiplies of 2.50.
the equation used is y = 2.50 * x
x is the number of tickets sold.
