Insert a column to the left of Column A

$4)$ Insert labels in A$5$ and A$6.$ Type "Sales" in A$5$ and "Net Income" in A$6.$

$5)$ Format Column A Width with $"20".$

$6)$ Insert label in A$7$: "Net Profit Margin"

$7)$ Type formula in B$7$: $=$B$6/$B$5$

$8)$ Pointer mode for formula in C$7$: $=$C$6/$C$5$

$9)$ Copy and move formulas

$10)$ Formatting B$7$:G$7$ percentage, two decimals