The sale price was $9,750 and we know that this amount is 90 % of the retail price. To solve this, let us formulate equation such as below:
Let RP be the retail price.
Let SP be the sale price.
Therefore,
RP x 0.9 = SP
RP x 0.9 = $9,750
RP = $9,750 / 0.9
RP = $ 10,833.33
The retail price was $10,833.33.