The local supermarket buys lettuce each day to ensure really fresh produce. Each morning, any lettuce that is left from the previous day is sold to a dealer that resells it to farmers who use it to feed their animals. This week, the supermarket can buy fresh lettuce for $10.00 a box. The lettuce is sold for $22.00 a box and the dealer that sells old lettuce is willing to pay $2.00 a box. Past history says that tomorrow's demand for lettuce averages 270 boxes with a standard deviation of 44 boxes. How many boxes of lettuce should the supermarket purchase tomorrow? Note: Use Excel's NORMSINV0 function to find the correct critical value for the given a-level. Do not round intermediate calculations. Round your answer to the nearest whole number