Question

if the median of the data 12,24,30,35,37,40,3m,3m+4,52,57,59,62,67,70 which is in ascending order is 47 find the value of m

Answer 1

n= 14 even
median of even = 1/2 ( n/2 + n/2+1) th term
47 = 1/2 (7th term + 8 th term)
47 =1/2 (3m+3m+4)
94= 6 m +4
90 = 6 m
m= 90/6
m= 15

this is your ans.
hope it helps you

Answer 2

number of terms in the given data = n=14 (even) 
median = average of ( n/2 and n/2+1) th terms

= avg [14/2 and (14/2+1)] th terms
= avg (7th and 8 th) terms
=avg[3m,3m+4)
=(3m+3x+4)/2
=(6m+4)/2
=3m+2----(1)

but given median = 47---(2)
(1) = (2)
3m+2 = 47
3m=47-2
3m=45
m=45/3
m= 15