[填空题]
The height of a baseball laying on* d *-rsb4yizx 2i2k*psht- klq8rh7 l the grounda3g aa4wvvy.+ is 73 mm.
1.Assuming that the baseball is a perfect sphere, calculate its volume in $mm^3$.Give your answer in the form $a\times 10^k$, where $1 \leq a \lt10$ and $k \in \mathbb Z$,correct to three significant figures. $\times10^5\: mm^3$
The volume of a volleyball is $4.64 \times 10^6 mm^3$.
2.Calculate how many times greater the volume of the volleyball is when compared to the baseball. Give your answer correct to the nearest whole number.
