$\frac{N+1}{2}=\frac{107+1}{2}$ th = 54th value i.e the median age is in the interval "7 - 8" (29 + 25 = 54)

Median = $1_m+(\frac{{}^{\sum f}{/}_2-f_b}{f_m})$c

$l_m$=lower class boundary of the median age = 6.5

$\sum f$ = 107

$f_b$ = sum of all frequencies before the median age = 29

$f_m$=frequency of the median age = 40

c = class width = 8.5 - 6.5 = 2

Median = 6.5 + $(\frac{{}^{107}{/}_2-29}{40})$ x 2

= 6.5 + $(\frac{53.5-29}{40})$ x 2

= 6.5 + $(\frac{24.5}{40})$ x 2

= 6.5 + 1.225

$\therefore$ median age = 7.725