Purple Crayon Company uses a standard cost system for its magenta crayons. The materials standard for each batch of crayons produced is 1.6 pounds of magenta coloring at a standard cost of $2.00 per pound. During the month of July, Purple purchased 64,000 pounds of magenta coloring at a total cost of $183,600. Purple used all of the magenta coloring to product 50,000 batches of crayons. What is Purples materials quantity variance for July?