Company A
we have the data set
23,29,35,46,51,50,42,37,30
Part 1
Find out the mean
mean=(23+29+35+46+51+50+42+37+30)/9
mean=343/9
mean=38.11
Part 2
Find out the median
Rewrite the data set, from less to greater
23,29,30,35,37,42,46,50,51
the median is the center
so
23,29,30,35,37,42,46,50,51
median=37
Q1=(29+30)/2=29.5
Q3=(46+50)/2=48
IQR=Q3-Q1=48-29.5=18.5
Part 3
Find out the standard deviation
For each data point, find the square of its distance to the mean
(23-38.11)^2=228.3121
(29-38.11)^2=82.9921
(35-38.11)^2=9.6721
(46-38.11)^2=62.2521
(51-38.11)^2=166.1521
(50-38.11)^2=141.3721
(42-38.11)^2=15.1321
(37-38.11)^2=1.2321
(30-38.11)^2=65.7721
Sum the values
Sum=772.8879
Divide by the number of data points
772.8879/9=85.8764
Take the square root
the result is 9.27
so
the standard deviation is 9.27