How to always get a positive output?

This is my code:

import random
minimum=int(input("Enter minimum value: "))
maximum=int(input("Enter maximum value: "))
if minimum>maximum:
    temp=minimum
    minimum=maximum
    maximum=temp
howMany = int(input("How many numbers do you want to generate?"))
sum=0
n=1
while n<=howMany:
    num=random.randrange(minimum,maximum)
    sum+=num
    n+=1
    print("Your random generated number is",num)
print("Python's random average between", minimum, "and", maximum, "is", sum/howMany)
avg=minimum+maximum/2
avgTwo=sum/howMany
difference=avgTwo-avg
print("The actual average of minimum and maximum is", avg)
print("The difference from the calculated average and from the actual average is", difference)

When I am calculating the difference, I need to always get a positive number. I tried flipping the variables being substracted but I received a negative number at random times.