Answer:
The net gain or profit is $600
Step-by-step explanation:
Firstly, we should know the losses of the customer which were:
9 when the customer bought 1 MCS Oct 50
1 when the customer bought back 1 MCS Jul 50
Therefore the total losses were 10.
And the gains were:
4 when the customer sold 1 MCS Jul 50
12 when the customer sold 1 MCS Oct 50
Therefore the total gains were 16.
Therefore (16 - 10)×100 = $600
Therefore the net gain or profit is $600
The distance between points
and
can be calculated using formula

1.

2.

3.

Then

Answer: correct choice is C.
Y is the independent variables
k is the dependent variable