4c. Consider an item with a single period of random demand. Your colleague has placed an order for 480 units and claimed to have used the optimal newsvendor solution. You know that demand is normally distributed with mean 500 and standard deviation 100, and that the overstock cost equals $30 per unit. What (approximate) value of understock cost did your colleague use in arriving at their order quantity? (You can enter a number rounded to one decimal place.)