Each year, a magazine compiles a list of the 400 richest people in a country. As of 2008, the top 10 on the list are as shown in the table below.
Person
A B C D E F G H I J
Wealth ($billions)
55.9 52.9 42.8 38.9 25.5 23.1 23.1 21.8 20.9 20.9
a. Find the mean.
b. Find the median.
c. Find the mode.