Question

if the mean of five observations,x,x+2,x+4,x+6 and x+8 is 13 , find x.

Answer 1

Mean = (x+x+2+x+4+x+6+x+8)/5

13=(5x+20)/5

13*5=5x+20

65=5x+20

65-20=5x

45=5x

45/5 =x

9=x


I hope this will help you


-by ABHAY

Answer 2

Hello friends!!!

Here is ur answer :

Mean = 13.

Total Numbers Of observations = 5

Sum of all the observations = x + x + 2 + x + 4 + x + 6 + x + 8 = 5x + 20


According to question,

$mean \: = \frac{sum \: \: of \: \: all \: \: observations}{total \: \: no. \: \: of \: \:observation }$

Put all the values.

$13 = \frac{5x + 20}{5}$


$13 \times 5 = 5x + 20$


$65 = 5x + 20$


$5x = 65 - 20$


$5x = 45$


$x = \frac{45}{5}$


$x = 9$


HOPE IT HELPS YOU...