Question: What is the function to calculate y when the quantity = x?

quantity price
100(min) $60
. .
x y
. .
100,000(max) $40

Please help need to solve urgently. Thank you so much in advance!

Question

Question: What is the function to calculate y when the quantity = x? 

quantity                                  price
100(min)                                $60
.                                             .
x                                            y
.                                             .
100,000(max)                       $40

Please help need to solve urgently. Thank you so much in advance!

directrix · Answer

I do not understand the question. Are you stating that 100 units of an item cost $60 and 100,000 units of the same items cost $40?

dumbcow · Answer

looks like a demand function which has an inverse relationship

y = k/x + c

60 = k/100 + c
and
40 = k/100,000 +c
solve for k and c

k = 2002
c = 39.98

y = 2002/x + 39.98

anonymous · Answer

Thank you so much! You don't know how much you helped. By the way how how did you find k and c?

dumbcow · Answer

you could also do a log regression but with only 2 points it may not be very precise

dumbcow · Answer

i put it in my calculator and got something like
y = 73.3 -2.9ln(x)

dumbcow · Answer

oh i just solved the system of 2 eqautions
i solved for c in 1st equation then substituted into 2nd equation to find k

anonymous · Answer

brilliant. Can't believe I've wasted a day trying to solve this. Thank you again!