Answer:
Option C is correct
$120
Step-by-step explanation:
The equation of best line is given by:
[tex]y=mx+b[/tex] ....[1]
where, y represents the total amount of money earned in tip after x hours, m is the slope and b is the y-intercept.
As per the statement:
From the graph:
Two points are:
(2, 20) and (8, 80)
Formula for slope(m) is given by:
[tex]m = \frac{y_2-y_1}{x_2-x_1}[/tex]
then;
[tex]m = \frac{80-20}{8-2}=\frac{60}{6}=10[/tex]
⇒m = 10
Substitute in [1] we have;
[tex]y = 10x+b[/tex]
Also , substitute the point (2, 20) to find b;
[tex]20= 10(2)+b[/tex]
⇒[tex]20=20+b[/tex]
Subtract 20 from both sides we have;
⇒0 = b
or
b = 0
Then, we get the equation:
[tex]y=10x[/tex]
We have to find total amount of money earned in tips after working 12 hours.
⇒x = 12 hours
then;
[tex]y=10(12) =120[/tex]
Therefore, the total amount of money earned in tips after working 12 hours is, $120
