Let’s go in parts, first convert all string values to integer, let’s go through the entire list for this. Converting one by one all list elements that are string, example:
x = ['11', '14', '152', '987']
novo_x = []
for i in x:
novo_x.append(int(i))
So you created a new list with the same values but now all are integer.
About the highest and lowest value... Without using max() and min() you will need to go through the entire list saving the highest and lowest value and go looking to see if you find another value higher or lower than the current one, example:
x = [11, 14, 152, 987]
Max = 0
for i in range(len(x)):
if(x[i] > Max):
Max = x[i]
output: 987
The average you can take the sum of all the values in the list using sum() divided by the total of items in the list using Len()... Getting:
x = [11, 14, 152, 987]
media = sum(x)/len(x)
-- Edit --
On the median... the colleague below, Peter corrected me:
The median is the value that separates the larger half and the smaller half of a sample, if this sample is even, the example I gave below applies, but if it is odd, follows the example that the colleague below gave.
x = [11, 14, 152, 987]
mediana = sum(x)/2
And what have you already done? In which part are you doubtful?
– Woss