The cost to produce 100 cupcakes is $126; while the cost to produce 120 cupcakes is $144: Suppose a straight line describes the data.
a) Find and interpret the slope of the cost line.
+37084 Equation for a line is y = mx + b where m = slope and b = y-axis intercept
You are given two points on the line 100, 126 and 120, 144
Slope = (y1-y2) / (x1-x2) ==== rise/run ===== (126-144)/(100-120) = -18/-20 = 9/10 = slope
so, so far y = 9/10 x + b
Substitute in either one of the points to calculate 'b'
126 = 9/10 ( 100) + b
126 = 90 + b
b = 36 = y- axis intercept y= 9/10 x + 36 is your line
