Suppose an online retail organization regularly changes the prices of their products (same product, but different prices from week to week). Changes in the product prices, as well as changes in how the products are advertised, will impact how many items are sold. In the model below, the item price and advertising budget are given in dollars. Predicted number of items sold = 40,000 - 450*(item price) + 0.8*(advertising budget) When the item price is $7 and the advertising budget is $1,000, then we predict that the number of items sold equals _______