 Solution

With $f=1_{\{\mathrm{font}=\mathrm{serif}\}}$ and $d=1_{\{\mathrm{display}=\mathrm{popup}\}}$, the model-matrix input isThe feedforward neural network has three inputs, a fully connected layer of two ReLU units, and a fully connected two-class softmax output. Algebraically,where $W\in {\mathbb{R}}^{2\times 3}$, $b\in {\mathbb{R}}^2$, $V\in {\mathbb{R}}^{2\times 2}$, and $c\in {\mathbb{R}}^2$. The coding is $0$ for no click and $1$ for a click. There areparameters.