CTET 2 Math and Science 23 Dec 2021 Paper

Question : 50 of 151

Marks: +1, -0

The mean of the five observations

{\x}+1, {\x}+2, {\x}+3, {\x}+6, {\x}+8

is 11 , Then, the mean of the three middle observations is

Solution:

11=\;{x+1+x+2+x+3+x+6+x+8}/{5}

By cross multiplication

⇒ 55=5 x+20

⇒ 35=5 x

⇒ x=7

Second observation

=7+2=9

Third obsevation

=7+3=10

Fourth observattion

=7+6=13

Mean

=

Sum of all items/Number of itmes

⇒ \;\text " Mean "\;=\;{9+10+13}/{3}

⇒ \;\text " Mean "\;=32 / 3

∴

Mean of three middle value is

32 / 3

The correct option is 3 i.e.

32 / 3

Go to Question:

Prev Question

Next Question