Question

the mean of 25 Observation is 36
out of these observation is the mean of first 13 observation is 32 and
that last 13 Observation is 40
. Find
The 13th Observation​

Answer 1

Answer:

x1+x2........x25/25 = 36

x1+x2........x25=36*25-----------(1)

x1+x2........x13/13 = 32

x1+x2.........x13=32*13--------(2)

similarly sum of last obs are

x13+x14........x25/13=40

x13...... x25=40*13------------(3)

from 1

(x1+......x13)+(x13........ +x25)-x13 = 36*25

from 2 and 3

32*13+40*13-x13=36*25

416+520 - x13 = 900

936-900 = x13

x13 = 36

Answer 2

Answer:

The 13th observation is 36

Step-by-step explanation:

mean=sum of observation/ no. of observation

Sum of observation=36(mean)×25(no. of observation)

=900 ------(1)

first 13 observation is 32×13=416

last 13 observation is 40×13=520

sum of first and last 13 observations(26 observations) = 936 ------(2)

subtraction of 26 observation- 25 observation I. e., (2)-(1)= 36