profit = revenue - cost
profit = 803.25 - 945
profit = -141.75
The negative profit indicates a loss
Loss percentage = (lossAmount/cost)*100%
Loss percentage = (141.75/945)*100%
Loss percentage = 0.15*100%
Loss percentage = 15%
The cooker lost 15% of its value when Mr Roberts sold it.
Or note how
revenue/cost = 803.25/945 = 0.85
Meaning that he was able to sell it for 85% of its original cost, therefore it lost 100% - 85% = 15% of its value.