#### Answer

The percent error is 0.44998%

#### Work Step by Step

We can find the number of seconds in one year. Let's assume that one year has 365.24 days per year.
$1 ~year = (365.24 ~days/year)(24 ~h/day)(3600 ~s/h)$
$1 ~year = 3.1557 \times 10^7~s$
A good approximation for the number of seconds per year is $\pi \times 10^7 ~s$. We can find the percent error in this approximation.
The percent error is:
$\frac{(3.1557 \times 10^7~s) - (3.1415 \times 10^7 ~s)}{(3.1557 \times 10^7~s)}\times 100\% = 0.44998\%$