The table is missing in the question. The table is attached below.
Solution :
Let X = appraised value
Y = area (square feet)
The regression line is given by :







The regression line is :

To estimate the error variance, we have:
Error variance, 


Answer:
20 masks and 100 ventilators
Step-by-step explanation:
I assume the problem ask to maximize the profit of the company.
Let's define the following variables
v: ventilator
m: mask
Restictions:
m + v ≤ 120
10 ≤ m ≤ 50
40 ≤ v ≤ 100
Profit function:
P = 10*m + 65*v
The system of restrictions can be seen in the figure attached. The five points marked are the vertices of the feasible region (the solution is one of these points). Replacing them in the profit function:
point Profit function:
(10, 100) 10*10 + 65*100 = 6600
(20, 100) 10*20 + 65*100 = 6700
(50, 70) 10*50 + 65*70 = 5050
(50, 40) 10*50 + 65*40 = 3100
(10, 40) 10*10 + 65*40 = 2700
Then, the profit maximization is obtained when 20 masks and 100 ventilators are produced.
<span>a=7b+8c+9d-10
a = 8c + 16d - 10
solve for c then
8c = a - 16d + 10
c = (</span>a - 16d + 10) / 8
or
c = a/8 - 2d + 5/4
Pemdas, ok first 17 plus 8 is 15, 6 times 2 is 12 , so 15 minus 12 is 3. answer is 3