inspections has columns inspection_id, grade and score.

Considering only the rows graded "A", return the tuple (variance, standard_deviation) of score as plain floats.

Use the population statistics, dividing by n rather than n - 1. Pandas defaults to the sample versions, so this needs saying explicitly.

Input

   inspection_id grade  score
0              1     A   95.0
1              2     A   88.0
2              3     B   70.0
3              4     A   99.0
4              5     C   60.0

Output

(20.666666666666668, 4.546060565661952)