Question

16. If the mean of the observations: x + 1, x +4, x + 5, x+8, x + 11 is 10, the mean of
the last three observations is
(A) 12.5
(B) 12.2
(C) 13.5
(D) 14.2
w125
22
0135
will​

Answer 1

Step-by-step explanation:

First we must find the value of x

therefore,

((x+1)+(x+4)+(x+5)+(x+8)+(x+11))/5=10

=((x+x+x+x+x) +(1+4+5+8+11))/5=10

=(5x+29)/5 =10

=5x+29 =5*10

=5x =50-29

=5x =21

=x =21/5

=x =4.2

Now we must find the last three terms, i.e.,

x+5 , x+8 & x+11

x+5

=4.2+5

=9.2

x+8

=4.2+8

=12.2

x+11

=4.2+11

=15.2

Now find the mean (average)

=(9.2+12.2+15.2)/3

=36.6/3

=12.2

Here is the answer

(B) 12.2