We have, 2, 4, 6, …… , 100 So, here n numbers in this A.P. series. We know that Tn=a+(n−1)d ⇒100=2+(n−1)2 ⇒n−1=49 ⇒n=50 Since there are 50, an even number of items . Therefore median is the arithmetic mean of (
50
2
)th and (
50
2
+1)th observations. So, 25th observation =2+(25−1)2=50 &26th observation =2+(26−1)2=52 Median =