Question

Mean of 8 observations is 25. If one observation 11 is excluded find the mean of theremaining​

Answer 1

Explanation:

let sum of obeservations=x

no.of observations. =8

x/8=25

x=200

11 is excluded from x

200-11=189

no.of obeservations is 7

189/7=27

Answer 2

Given :

• Mean of 8 observations = 25

To Find :

• Mean of the remaining observations when one observation 11 is excluded

Solution :

Mean is gicen by ,

$\\ \star \: {\boxed{\purple{\sf{Mean = \frac{Sum \: of \: observations}{Number \: of \: observations} }}}}$

We are given that mean of 8 observations as 25.

$\\ : \implies \sf \:25 = \frac{sum \: of \: observations}{8}$

$\\ : \implies \sf \: 25 \times 8= sum \: of \: observations$

$\\ : \implies{\underline{\boxed {\red{\mathfrak{sum \: of \: observations = 200}}}}}$

We got the sum of observations (including 11) as 200.

Sum of observations when 11 is excluded is 200 - 11 = 189.

So , Sum of observations (when 11 is excluded) is 189.

When 1 observation is excluded from 8 observations , then number of observations are 7

Now , Calculating the mean for the remaining observations ;

$\\ : \implies \sf \: mean = \frac{189}{7}$

$\\ : \implies{\underline{\boxed {\pink{\mathfrak{mean = 27}}}}} \: \bigstar \:$

Hence ,

• The mean of the remaining observations is 27.