What is the arithmetic mean in the following table on the variable score?

$\backslash$table$[[$Student$\_$ID$,$Score$],[$R$304110,0\mathrm{.}99],[$R$304003,0\mathrm{.}82],[$R$102234,0\mathrm{.}65],[$R$209939,0\mathrm{.}92]]$