grades = [100, 100, 90, 40, 80, 100, 85, 70, 90, 65, 90, 85, 50.5]

def print_grades(grades_input):

for grade in grades_input:

print grade

def grades_sum(scores):

total = 0

for score in scores:

total += score

return total

def grades_average(grades_input):

sum_of_grades = grades_sum(grades_input)

average = sum_of_grades / float(len(grades_input))

return average

def grades_variance(scores):

average= grades_average(scores)

variance=0

for score in scores:

variance+=(average-score)**2

return variance/len(scores)

print grades_variance(grades)

def grades_std_deviation(variance):

return variance**0,5

variance=grades_variance(grades)

print grades_std_deviation(variance)

INSTRUCTIONS:

Define a function, grades_std_deviation, that takes one argument called variance.

return the result of variance ** 0.5

After the function, create a new variable called variance and store the result of calling grades_variance(grades).

Finally print the result of calling grades_std_deviation(variance).

ERROR TYPE:

grades_std_deviation(20.25) returned (1.0, 5) instead of the expected: 4.5