See photos for solutions and steps :)
 
        
        
        
The best prediction for the number of customers is 5450.
To find this value, you just need to plug in 20 for x into the expression. Then, evaluate it using the order of operations.
8(20)^2 + 100(20) + 250
8(400) + 100(20) + 250
3200 + 2000 + 250
5450
        
             
        
        
        
4.16 / 5.20 = 1 / x.....4.16 lbs to $ 5.20 = 1 lb to $x
cross multiply because this is a proportion
(4.16)(x) = (5.20)(1)
4.16x = 5.20
x = 5.20 / 4.16
x = 1.25 per lb <==