Question

find the mean and median of first 12 odd composite numbers

Answer 1

the composite numbers are:9,15,21,25,27,33,35,39,45,49,51,55
total=404
mean:total/ number of composite numbers
=404/12
=33.6

median:(33+35)/2
=68/2
=34

hope it might help you

Answer 2

The mean = 33.67 and median = 34

Explanation:

The first 12 odd composite numbers are:

9, 15, 21, 25, 27, 33, 35, 39, 45, 49, 51 and 55

To find, the mean and median = ?

Here, number of observation = 12

We know that,

Mean $=\dfrac{Sum of all observations}{Total number of observations}$

$=\dfrac{404}{12}$

$=\dfrac{101}{3}=33.67$

Here, number of observation = 12 (odd number)

Median $=\dfrac{The value of \dfrac{n}{2}th observation+The value of (\dfrac{n}{2}+1)th observation}{2}$

$=\dfrac{The value of 6th observation+The value of 7th observation}{2}$

$=\dfrac{33+35}{2}$

$=\dfrac{68}{2}$

= 34

Hence, the mean = 33.67 and median = 34.