In task is wrong formula.
04 for each score in scores: Compute its squared difference: (average - score) ** 2 and add that to variance.
Correct formula should be:
(score - average) ** 2
(1/Number of occurrences) * Summation (sigma symbol) i = 1 to Number of occurrences (xi - average) **2
def grades_variance(scores): average = grades_average(scores) variance = 0 for score in scores: variance += (score - average) ** 2 return variance/len(scores)