Finding the cost
To find the cost of the oak table, subtract the markup to the sell price
$69.99 - $21.72 = $48.27
The cost of the oak table therefore is $48.27.
Next, divide the markup to the cost of the oak table to determine the percent of markup.
$21.72 ÷ $48.27 = 0.4499689
Multiply the result by 100%
0.4499689 × 100% = 44.99689%
Rounding off to the nearest tenth of a percent, the percent of mark up is 45.0%