b$.$ Comment briefly on the changes between the two years.

Although sales revenue increased $33\mathrm{.}3\%,$ cost of goods sold increased only $20\mathrm{.}4\%.$

As a result, gross profit increased $54\mathrm{.}4\%.$ The firm's selling prices are apparently increasing

at a faster pace than product costs.

A favorable aspect is that selling expenses increased by only $6\mathrm{.}1\%$

compared with the $33\mathrm{.}3\%$ increase in sales.

Also, administrative expenses increased $20\mathrm{.}0\%,$ and total expenses increased only $10\mathrm{.}7\%.$

The smaller increase in expenses enabled the firm to increase its income before

income taxes by $350\mathrm{.}0\%$ and net income by $400\mathrm{.}0\%.$