Answer
$1.5\times10^{-12}F$
Work Step by Step
Equation 21-19 gives the resonant frequency of a LC circuit.
$$f_o=\frac{1}{2 \pi}\sqrt{\frac{1}{LC}}$$
$$C=\frac{1}{4\pi^2Lf_o^2}$$
$$C=\frac{1}{4\pi^2(1.8\times 10^{-6}H)(98.3\times10^6Hz)^2}=1.5\times10^{-12}F$$
