9 Exam Statistics

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

  variance /= float(len(scores))

  return variance

def grades_std_deviation(variance):

  return variance ** 0.5

variance = grades_variance(grades)

print print_grades(grades)

print grades_sum(grades)

print grades_average(grades)

print grades_variance(grades)

print grades_std_deviation(variance)