Exercise 3.22 - Fitting a naive Bayesian spam filter by hand

${𝜃}_{\text{spam}}$ is $\frac{3}{3+4}$.

${𝜃}_{\text{secret}|\text{spam}}$ is $\frac{2}{3}$.

${𝜃}_{\text{secret}|\text{non-spam}}$ is $\frac{1}{4}$.

${𝜃}_{\text{sports}|\text{non-spam}}$ is $\frac{1}{2}$.

${𝜃}_{\text{dollar}|\text{spam}}$ is $\frac{1}{3}$.