My dataset look similar to this

Id MathBaseline. WPMBaseline. NepaliBaseline MathPost WPMPost NepaliPost
1 Add 5 2 Multiply 10 3
2 Add 5 2 Multiply 11 3
3 Add 2 4 Subtract 20 4
4 Add 6 2 Multiply 10 3
5 Add 5 2 Multiply 11 3
6 Add 5 4 Subtract 20 4
7 Add 5 4 Subtract 20 . (missing value)
8 Add 5 4 Subtract 20 . (missing value)


My Question is:
1. Is there a way to find mean at WPMPost for which WPMBaseline is equal to 5?

2. Is there a way to find all the missing values at NepaliPost when NepaliBaseline=4?