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 $0.80 per card, and the cost of printing is $0.30 per card. The company receives $3.10 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 7,750 and a standard deviation 100. (Assume these four are independent.) What is the optimal production quantity for the card? Note: 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