#Previous funtion
def compute_mean(my_list):
    number_list = my_list
    total = 0
    for number in number_list:
        total = total + float(number)
    return total / len(number_list)

#The function I'm working on
def compute_sd(my_list):
    list_of_numbers = my_list
    sum = 0
    for num in list_of_numbers:
        mean = my_list
        dev = num - mean
        var = sum((l-mean)**2 for l in list) / len(list)
        dev = math.sqrt(var)

    return dev

This is what I have so far, and I'm stumped.

In this step we will write a function (compute_sd) to calculate the standard deviation of the numbers in a list. It will receive a list of integer numbers as parameter and will return the standard deviation of the numbers in the given list. It will complete the task as follows:

· Use compute_mean function to calculate mean of the numbers in the list

· Initialize sum to 0

· Use definite loop (for num in list_of_numbers)

o Calculate deviation by subtracting mean from the num

o Calculate the square of the deviation

o Add the square of the deviation to sum

· Calculate the size of the list

· Divide sum by the size-1 to compute the result.

· Take the square root of the result to compute the standard deviation.

· Return the standard deviation of the numbers in the list.