Management firms are investment companies that invest people's funds in securities.

Step-by-step explanation:

a )

sample mean = sum total of given data / no of data

= 415.35 / 20 = 20.76

To calculate the median we arrange the data in ascending order and take the average of 10 th and 11 th term .

= 20.50 + 20.72 / 2

= 20.61

b ) To calculate the 10% trimmed mean , we neglect the largest 10% and smallest 10 % data and then calculate the mean . Here we neglect the first two smallest and last two greatest

(18.92 + 19.25 + 22.43 + 22.85) / 16

= 20.74

c )

We can easily plot the data on number line from 17 to 24

d )

Maximum value of data set = 23.71 and minimum value is 18.04

mean is 20.76 , median is 20.61 and trimmed mean is 20.74

They are between maximum and minimum values of given data . Hence there is no outliers .