The RBB distributes various pharmaceutical products. When he receives the 50-unit lots from one of his suppliers, he checks their weight to make sure the order is correct. For this, it performs a double sampling that is applied as follows: It takes a sample of 12 and weighs them to calculate their average; then he takes a second sample of 6, weighs them, and takes their average. If the second average weighs between 1 and 2 pounds or between 1.5 and 2.5 pounds more than the first, the lot is returned to the supplier. What will be the IP to return the batch? Assume that the samples returned standard deviations of 2.5 and 3 pounds, respectively.