Compute the Average

The answer is 499 .

Iterate through the list, keeping track of the sum and the total number of integers as you go. When you reach the end of the list, compute the average by dividing the total sum by the number of integers.

Integer Division : When you divide two integers, the result will be rounded down. To preserve the decimal values so you can round correctly, make sure your sum is a non-integer type, such as a float.

Python solution:

# open file in read mode
f = open('cs_avgnums.txt', 'r') 

sum = 0.0 # sum is a float, to avoid integer division
num_ints = 0

# for each line in the file, add to sum and increment num_ints
for line in f: 
    num_ints += 1 
    sum += int(line)
avg = sum / num_ints
print int(round(avg)) 

f.close()