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Problem 11-7 (Algo) Wholemark is an Internet order business that sells one popular New Year's greeting card once a year. The cost of the paper on which the card is printed is $0.85 per card, and the cost of printing is $0.35 per card. The company receives $3.60 per card sold. Since the cards have the current year printed on them, unsold cards have no salvage value. Its customers are from the four areas: Los Angeles, Santa Monica, Hollywood, and Pasadena. Based on past data, the number of customers from each of the four regions is normally distributed with a mean of 6,900 and a standard deviation 480. (Assume these four are independent.) What is the optimal production quantity for the card? (Use Excel's NORM.S.INV() function to find the z value. Round z value to 2 decimal places. Round your answer to the nearest whole number.) X Answer is complete but not entirely correct. Optimal production quantity 7,319