susan has been making soy candles for friends and family for many years. recently she debated making an official website to sell her candles to the general public. her variable cost is $4.95 per unit, and she would sell each candle for $11.00. her fixed costs will be $400 per month. how many units would she need to sell per month, on average, to completely replace her monthly salary of $4320? 647 units 780 units 648 units 296 units