Answer:
I dont have flowgorithm right now but you need to make loop with counter 1-20 every time it do loop it should increase some counter variable by one and take input. When it does loop 20 times it should calculate average by formula average=(a1 + a2 × a3 + a4 .... + a20)/20. Then make new loop where it will write the difference. So you should make same loop as in begining with some counter variable 1-20, where it should write average - ai.
