The wholesaler's markup is the difference between the selling price and the cost price, which is $80.43 - $73 = $7.43.
The markup rate can be found by dividing the markup by the cost price and multiplying by 100 to get a percentage:
markup rate = (markup / cost price) x 100%
markup rate = ($7.43 / $73) x 100%
markup rate = 10.17%
Therefore, the wholesaler's markup rate is 10.17%, rounded to the nearest hundredth.