Question

the mean of five number is 27. If one number is excluded their mean is 25 .Find the excluded observation

Answer 1

Find the sum of 5 numbers:

Mean of 5 numbers = 27

Sum of 5 numbers = 27 x 5 = 135

Find the sum of the 4 numbers:

Mean of the 4 numbers = 25

Sum of the 4 numbers = 4 x 25 = 100

Find the excluded observation:

135 - 100 = 35

Answer: The excluded observation is 35

Answer 2

Answer:

35

Step-by-step explanation:

We are given that the mean of five number is 27.

$Average = \frac{\text{Sum of 5 numbers}}{5}$

$27= \frac{\text{Sum of 5 numbers}}{5}$

$27 \times 5= \\text{Sum of 5 numbers}$

$135= \\text{Sum of 5 numbers}$

One number is excluded their mean is 25

Let the excluded number be x

So, new sum = 135-x

No. of observations = 5-1 =4

$Average = \frac{\text{New sum}}{4}$

$25 = \frac{135-x}{4}$

$25 \times 4 =135-x$

$100 =135-x$

$x=35$

Hence the excluded observation is 35