Four order pairs are ( 2, 5 ), ( 4, 8 ), ( 6, 11 ), ( 0, 2). All those I cited are whole numbers so that should help plot them, and from there get a ruler or straight edge and align all the dots to create the line for the equation. The equation you gave was the standard form which was created out of the formula to find a equation it's y = mx + b, there could be small variations made. How I know it's proportional is because all linear equations are. But if that's not enough I also know since there's a ratio or pattern that it follows and doesn't stray from. In more depth, porportional relationship is a ratio between y and x which is the same thing everytime shown if simplified.
To find the total from the percent part you have, you divide the part by the percentage. 1.50÷0.05=30 The total is $30 The total the store charged, including sales tax, is $31.50.
