A manufacturer gets a shipment of 520 batteries of which 26 are defective. The store manager wants to be able to test random samples in future shipments. She tests a random sample of 20 batteries in this shipment to see whether a sample of that size produces a reasonable inference about the entire shipment. Fill in the blanks to make this statement true. The manager selects a random sample using the formula randInt,(1 ) to generate random numbers.