Answer
Please see the work below.
Work Step by Step
We can find the percent error as below
$\%error=\frac{actual \space value-estimated \space value }{actual \space value}\times 100$
We plug in the known values to obtain:
$\%error=\frac{(3.156\times 10^7)-(\pi\times 10^7)}{3.156\times 10^7}\times 100$
$\%error=0.457\%$
