Question

he mean of 25 observations is 36. Out of these observations if
the mean of first 13 observations is 32 and that of the last 13
observations is 40, the 13th observation is:
(A) 23
(B) 36
(C) 38
(D) 40
ОА
OB
O
С
OD​

Answer 1

Answer:

sum of all observation=25×36=900

• sum of first 13 observation=32×13=416
• sum of last 13 observation=40×13=520
• sum of 26 observation=416+520=936
• thirteenth observation is taken twice that's why thirteenth observation will be 936-900=36