1. Dan does an experiment to find the value of $\pi .$
He measures the circumference and the diameter of a circle.

He measures the circumference, $C,$ as $170$ mm to the nearest millimetre.
He measures the diameter, $d,$ as $54$ mm to the nearest millimetre.

Dan uses $\pi =\frac{C}{d}$ to find the value of $\pi$.
Calculate the upper bound and the lower bound for Dan's value of $\pi .$