Answer:
Later it is found that the item 62 is wrongly written as 26 ,
∴ Difference = 62 – 26 = 36
∴ Required average = 47 +36
20
Required average = 47 + 1.8 = 48.8
Second method to solve this question with the help of given formula :
Here, n = 20 , m = 47 , a = 62 , b = 26
Correct Average = m + (a-b)
n
Correct Average = 47 + (62-26)
20
Correct Average = 47 +36
20
Correct Average = 47 + 1.8 = 48.8