Question

Mean of 15 observations is 18. If one observation is included, their mean
becomes 19. Find included observation.
​

Answer 1

given

• mean of 15 observation is 18

To find

• number included if mean become 19

solution

x/15=18. (given)

x=18 x 15

x=270. equation (1)

if we add one more observation mean became 19

let the number included be y

x+y/16=19

from equation (1) put value of x

270+y=19*16

270+y=304

y= 304-270

y= 34

number included is 34

Thanks

hope its helpful