Answer
1.1 $\times$ $10^{6}$
Work Step by Step
We can figure out the appropriate number of significant figures by looking at the number with the least precision, which is 0.000456. Since 0.000456 has three significant figures, the final answer must also be quoted to three significant figures.
$\frac{8.21\times10^{4}\times1.3\times10^{-3}}{0.00236\times4.071\times10^{-2}}$ = $1.1\times10^{6}$
