Answer
$1.331928\times10^{13} \text{ tons}$
Work Step by Step
Using $D=\dfrac{M}{V}$ or the density of an object, then
\begin{array}{l}\require{cancel}
D=\dfrac{M}{V}
\\
3.12\times10^{-2}=\dfrac{M}{4.269\times10^{14}}
.\end{array}
By cross-multiplication, then
\begin{array}{l}\require{cancel}
M=(3.12\times10^{-2})(4.269\times10^{14})
\\
M=(3.12)(4.269)\times(10^{-2})(10^{14})
\\
M=13.31928\times(10^{-2})(10^{14})
.\end{array}
Using the Product Rule of the laws of exponents which is given by $x^m\cdot x^n=x^{m+n},$ the expression above is equivalent to
\begin{array}{l}\require{cancel}
M=13.31928\times10^{-2+14}
\\
M=13.31928\times10^{12}
\\
M=1.331928\times10^{13}
.\end{array}
Hence, the mass is $
1.331928\times10^{13} \text{ tons}
.$