Let's find the mean of all the values first.
6.3+6.4+6.5+6.6+6.8+6.8+7.5= 46.9
Let's divide by the number of values.
46.9÷7=
6.7
Now let's find the distance that each number is away from 6.7 and find the mean of those numbers.
0.4+0.3+0.2+0.1+0.1+0.1+0.8=
.2857
≈ 0.3
So, the absolute deviation is 0.3.
You find the x coordinates using x = -b/2a = -6/2(-1) = 3
Substitute 3 in the equation and find y
y = -(3^2) + 6(3) - 12 = -9 + 18 - 12 = -3
Vertex (3,-3)
Let A represent amount of Type A coffee pounds used.
Let B represent amount of Type B coffee pounds used
A + B = 156
B = 156 - A
A = 156 - B
5.80A + 4.65B = 826.60
580 (156 - B) + 4.65B - 826.60 = 0
904.8 - 5.80B + 4.65B - 826.60 = 0
904.8 - 1.15B - 826.60 = 0
78.2 - 1.15B = 0
78.2/1.15 = 1.15B/1.15
68 = B
B = 68 pounds of Type B coffee
There's many more steps you can take to check and etc but am too lazy to put down sorry.