The price that Amazon has to establish for their online shopping should be $20.
We have the price function as
P = 10 + 2Qi
Make Qi subject
= Qi = 0.5P - 5
4 firms with identical features
This would give us Â
Qs = 4Qi
Qs = 4(0.5P -5)
Qs = 2p - 20
Q = 100 - 2p
Qa = Q - Qs
(100 - 2P) - (2P -20)
Take like terms
100 - 2p - 2p + 20
100 - 4p + 20
Qa = 120 - 4p
Make p subject
p = 120 - Qa / 4
p = 30 - 0.25Qa
TRa = p*Qa
= (30 - 0.25Qa)Qa
= 30Qa - 0.25Qa²
MRa
= Â 30 - 0.5Qa
TCA = 10 + 10QA
=  ΔTCA / ΔQA
= 10
30 - 0.5QA = 10
Take like terms
30 - 10 = 0.5Qa
divide through by 0.5
20/0.5 = Qa
40 = Qa
Output produced = Â 40.
We have P as
30 - 0.25QA
P = 30 - 0.25( *40)
= 20
Hence the price that Amazon has to establish for the online shopping should be $20
Read more on marginal costs here:
https://brainly.com/question/17230008
#SPJ1