Answer
$1.59\times 10^{-19}C$
Work Step by Step
$ 1.60\times 10^{-19}/1=1.60\times 10^{-19}$
$3.15\times 10^{-19}/2=1.58\times 10^{-19}$
$4.81\times 10^{-19}/3=1.60\times 10^{-19}$
$6.31\times 10^{-19}/4=1.58\times 10^{-19}$
We calculate the average and round it to 3 significant figures:
$\frac{1.60\times 10^{-19}+1.58\times 10^{-19}+1.60\times 10^{-19}+1.58\times 10^{-19}}{4}\approx 1.59\times 10^{-19}$
