The answer from the given option is The mean study time of students in class B is less than the students in class A.
Explanation:
There are three types of mean:
Here in class A,
Mean in class A = (2+5+7+6+4+3+8+7+4+5+7+6+3+5+4+2+4+6+3+5) / 20
= 4.8.
Mean in class B = (3+7+6+4+3+2+4+5+6+7+2+2+2+3+4+5+2+2+5+6) / 20
= 4.
Hence mean study time of class B is less than the mean study time of class A.