N+12=107+12 th = 54th value i.e the median age is in the interval "7 - 8" (29 + 25 = 54)
Median = 1m+(∑f∕2−fbfm)c
lm=lower class boundary of the median age = 6.5
∑f = 107
fb = sum of all frequencies before the median age = 29
fm=frequency of the median age = 40
c = class width = 8.5 - 6.5 = 2
Median = 6.5 + (107∕2−2940) x 2
= 6.5 + (53.5−2940) x 2
= 6.5 + (24.540) x 2
= 6.5 + 1.225
∴ median age = 7.725
