You would round it to 656.70 because the 9 behind the 6 is greater than 5 so it rounds up and makes 6 and 7 and all the numbers behind 6 zero.
The percent of the increase is

I is the increasing value
N is the new value
O is the original value
The price of the cooler is $28.50, then
O = 28.50
The selling price of the cooler is $40.76, then
N = 40.76
We will substitute them in the rule above to find I

Let us calculate it
I = 43.0175 %
Round it to the nearest percent
I = 43%
The answer is D
The equation of the line that is // to the given equation MUST HAVE THE SAME SLOPE.
The slope of the hiven equation is the number next to x or 3.
See it?
We know the slope is 3 and one point is given.
We now use the point-slope formula to find the equation.
y - y_1 = m(x - x_1)
See picture. The answer is y = 3x - 7.
Smaller x = -2/5
Larger x = 5