Let’s see how the grades varied against the average. This is called computing the variance.
A very large variance means that the students’ grades were all over the place, while a small variance (relatively close to the average) means that the majority of the students had similar grades.
Instructions
On line 18, define a new function called grades_variance
that accepts one argument, scores
, a list.
First, create a variable average
and store the result of calling grades_average(scores)
.
Next, create another variable variance
and set it to zero. We will use this as a rolling sum.
for
each score in scores:
Compute its squared difference: (average - score) ** 2
and add that to variance
.
Divide the total variance
by the number of scores
.
Then, return that result.
Finally, after your function code, print grades_variance(grades)
.