You have to do subtract 10 from 4 because 6 is how much we will profit from each shirt. Now, 6 times 327 is $1,962. That's how much Timothy earned of profit.
To find the midpoint you find the average x and the average y values. The average of 1 and 9 is 5, and the average of 4 and 16 is 10. The midpoint would be (5,10).