Answer:
A. y = 3x/4
Step-by-step explanation:
a proportional relationship between x and y is a straight line passing through the origin (0, 0).
The equation must be in the form y = kx.
y = 3x/4
y = 3/4x
You could multiply 19.45 by 0.2 to solve for it, but if you're not using a calculator, then 19.45/5 would be much more convenient and easier.
0.2 is 1/5 in fraction form, which is why we can do that.
19.45/5 = 3.89
Dino should leave $3.89 as a tip.
To find this out, use a percent proportion, use cross products, and solve the equation.

So, the percent tip is 14%.