Standard Deviation


#1

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

def print_grades(grades):
for grade in grades:
print grade

def grades_sum(grades):
total = 0
for grade in grades:
total += grade
return total

def grades_average(grades):
sum_of_grades = grades_sum(grades)
ave = sum_of_grades / float(len(grades))
return ave

def grades_variance(scores):
average=grades_average(scores)
variance=0
for score in scores:
variance+=(average-score)**2
kite = variance / float(len(scores))
return kite

def grades_std_deviation(variance):
variance=grades_variance(grades)
result=variance ** 0.5
return result

print grades_std_deviation(variance)

Oops, try again. grades_std_deviation(2.25) returned 18.2776094147 instead of the expected: 1.5


#2

variance=grades_variance(grades)

this should be last line in fucntion


#3

variance=grades_variance(grades)
write it before the last function....