Step-by-step explanation:
(b) If
then
Note that
cancel out so we get

Solving for
we get

(c) I'm not sure what the problem is asking for but here goes. As r doubles,
becomes

Answer:
542.50
Step-by-step explanation:
Given:
Least square regression equation :
y = 102.50 + 0.65x + residual
y = predicted fare
x = distance in miles
Intercept = 102.50
Slope = 0.65
Distance in miles, x = 500 miles
y = 102.50 + 0.65(500) + 115
y = 102.50 + 325 + 115
y = 427.5 + 115
y = 542.50
Function:(7,-4), (0,9), (2,-2)
(-6,5),(-5,6), (8,2)
(2,3),(6,-5),(-1,3)
Not a function:(0,3),(0,7),(4,0)
(1,9),(-3,-2),(1,-4)
Coefficient is a number next to the variable so the coefficient of this expression is 3/8