Answer
$T = 8.77~s$
Work Step by Step
We can find the original length $L$ from the pivot to the center of mass:
$T = 2\pi~\sqrt{\frac{L}{g}}$
$\frac{T}{2\pi} = \sqrt{\frac{L}{g}}$
$\frac{T^2}{4\pi^2} = \frac{L}{g}$
$L = \frac{T^2~g}{4\pi^2}$
$L = \frac{(8.85~s)^2~(9.8~m/s^2)}{4\pi^2}$
$L = 19.44~m$
The new length between the pivot and the center of mass is $L = 19.09~m$
We can find the new period:
$T = 2\pi~\sqrt{\frac{L}{g}}$
$T = 2\pi~\sqrt{\frac{19.09~m}{9.8~m/s^2}}$
$T = 8.77~s$
