Question

Mean of total 9 observation is 13. If the mean of first five observations is 12 and last five observations is 14 .find the fifth observation

Answer 1

Answer: 5

Step-by-step explanation:

mean is the average of the data

mean of 9 observations = 13

i.e sum of 9 observations = 117

mean of  first 5 observations = 12

i.e sum of first 5 observations = 60

mean of last 5 observations = 14

i.e sum of last 5 observations = 70

one observation is repeated in both sets => difference of the  sum of first 5 and last five observations = 10

average of the difference = 10/2 = 5