$10\mathrm{.}5.$ Weights $W_1$ and $W_2$ of the rotor in Fig. $10\mathrm{.}32$ rotate in the transverse planes shown. Determine the weights $W_3$ and $W_4$ in planes $3$ and $4,$ respectively, which give dynamic rotating balance. Show the correct angular positions of $W_3$ and $W_4.$

$W_1=8ib$

$W_2=20ib$

$r_1=5in.$

$r_2=71in..$

$r_2=4in..$

$r_4=4in.$

FIGURE $10\mathrm{.}32$