APPROXIMATE THE MEAN

APPROXIMATE THE MEAN OF THE GROUPED DATA.
THE AGE DISTRIBUTION OF STUDENTS I A STATISTICS CLASS.
AGE: 20-29 30-39 40-49 50-59 60-69

FREQUENCY: 24 21 21 22 6

WHAT IS THE MEAN AGE OF THE STUDENTS BASED ON THIS GIVEN FREQUENCY DISTRIBUTION?
(ROUND TO THE NEAREST HUNDREDTH)

PLEASE EXPLAIN THE ANSWER?
THANK YOU