Question 254800
let C(x) is the cost to produce x cups of coffee and is given by

C(x)=ax+b where a and b are constants (given C(x) is a linear function of x)

now given x=100 and C(x)=11.02 =>  11.02=100a+b  ------1

and       x=400 and C(x)=40.12 =>  40.12=400a+b -------2

subtract eq 1 from eq 2 

we get  29.1=300a

so a=0.097

put this value of a in eq 1

we get 11.02=9.7+b

so b=1.32

so the function is C(x)=0.097x+1.32