Question

The mean of five observation is 17. If the mean of first three observation is 15 and the last three is 18. Find the third observation.

Answer 1

See,
Sum of Observation = Mean*Number of Observation..

Answer 2

i did'nt understand the question!
please can u explain.

Answer 3

Sum of 5 observation = 17*5 = 85

first(2) + x = 15*3 = 45 (x is the third observation) ---------1

x + next(2) = 18*3 = 54 -------------2


Now add both the equations and subtract x:

(first(2) + x) + (x + next(2)) - x = 85

45 + 5 4 - x = 85

99 - x = 85

x = 14

So, the third observation is 14...

Answer 4

are u sure?

Answer 5

Yes why not.

Answer 6

thank you:)

Answer 7

there is one more to solve, can u help?

Answer 8

Yes sure..

Answer 9

The mean of ten observations is found to be 10. Later on, it was found that the observation 21was misread as 12. Find the correct mean.

Answer 10

See first find the sum of observation..
You have 10 observation and mean = 10
use the above formula..

Answer 11

sum of observation is 100.

Answer 12

In sum there is one term that is 12 and if we want to make it 21 so what number i will add to 12 to get 21?

Answer 13

9

Answer 14

after that?

Answer 15

hey! please help me!!!!!!

Answer 16

Yes add 9 to the sum of observation..

Answer 17

109

Answer 18

109-100=9 like that??

Answer 19

109 is the right one..

Answer 20

answer =109

Answer 21

yaa?

Answer 22

now divide it by 10 to get the mean..

Answer 23

10.9

Answer 24

is it?

Answer 25

Yes this is it..

Answer 26

thnx :)