Answer
Radius is about 4.63 mm
Work Step by Step
Formula for the volume of sphere [$V=\frac{4}{3}\pi{r}^{3}$]
one larger sphere = (sphere of radius 2) +(sphere of radius 3) +(sphere of radius 4)
$V= \frac{4}{3}\pi(2)^{3}+\frac{4}{3}\pi(3)^3+\frac{4}{3}\pi(4)^3$
$V =\frac{4}{3}\pi(2^3+3^3+4^3)$
$r^{3}=2^{3}+3^{3}+4^{3}$
$r^{3}=8+27+64$
$=99$
$r=\sqrt[3] 99$
Put it in the calculator
r=4.6261
