Answer
See the answer below.
Work Step by Step
Volume of tin atom:
$4/3.\pi.(141\ pm)^3=11.74\times 10^6\ pm^3$
White tin:
$4\times 11.74\times 10^6\ pm^3\div[(583\ pm)^2\times 318\ pm]\times 100\%=43.46\%$
Gray tin:
$8\times 11.74\times 10^6\ pm^3\div(649\ pm)^3\times 100\%=34.37\%$
