Question

The final inspection of nine aircraft revealed the following numbers of missing rivets:

8        16        14        19        11        11        15        10        21

                What is the mean, midrange, median and mode?

Answer 1

Solution

The sample mean is

Mean = (x / n) )

= ( 8+16+14+19+11+11+15+10+21 / 9 )

=125 /9

=13.8889

Mean = 13.89

Mid range = Maximum value + Minimum value / 2

= 21+ 8 / 2

= 29 /2

= 14.5

Mid range = 14.5

Median :
Observations in the ascending order are :
8,10,11,11,14,15,16,19,21

Here, n=9 is odd.

M= value of (n+12)^th observation

= value of (9+12)th observation

= value of 5^th observation

=14

Median = 14

Mode :
In the given data, the observation 11 occurs maximum number of times (2)

∴Z=11