Question

If the mean of x, x + 3, x = 5, x + 7, x + 10 is 9, then find the mean of lost 3 observations

Answer 1

Correct Question :-

If the mean of x, x + 3 , x + 5 , x + 7 , x + 10 is 9 then find the mean of last 3 observations.

Solutions :-

Given observations are

x, x + 3 , x + 5 , x + 7 , x + 10

The mean of the given observation is 9

As we know that,

Mean = Sum of observation / Total observations

So,

According to the question,

x + x + 3 + x + 5 + x + 7 + x + 10 / 5 = 9

5x + 25 = 45

5x = 45 - 25

5x = 20

x = 20/5

x = 4

Thus, The value of x is 4

Now,

we have to find the mean of last 3 observations

Therefore,

x + 5 + x + 7 + x + 10 / 3

Subsitute the value of x here,

4 + 5 + 4 + 7 + 4 + 10 / 3

= 34/3

= 11.33

Hence, The mean of last 3 observations is 11.33 $.$

Answer 2

*Answer:-

We know that,

• Average of a data = sum of total observations / total number of observations

According to the question

• (x + x+3 + x+5 + x+7 + x+10)/5
• = 9 (5x +15)/5 = 9 x + 3 = 9 x = 6

Now, the terms become,

• 6, 6 + 3, 6 + 5, 6 + 7, 6 + 10 = 6, 9, 11, 13, 16

So, the mean of the last three observations

• = ( 11 + 13 + 16)/3 = 40/3 = 11.33

$hope \: it \: helps \: you$