Traceback (most recent call last):
File "python", line 30, in
File "python", line 26, in grades_std_deviation
TypeError: unsupported operand type(s) for ** or pow(): 'list' and 'float'
I can't figure out what is wrong here. I have it exactly as the instructions say, and I've looked through the relevant forum posts to confirm, but I still get an error.
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) average = sum_of_grades / float(len(grades)) return average def grades_variance(scores): average = grades_average(scores) variance = 0 for score in scores: variance += (average - score) ** 2 return variance / (len(scores)) def grades_std_deviation(variance): return variance ** 0.5 variance = grades_variance(grades) print grades_std_deviation(grades)