A manufacturer of small appliances purchases coffeepot handles from an outside vendor. If a handle is cracked, it is considered defective and can't be used. A large shipment of plastic handles is received. How many handles from the shipment should be inspected in order to estimate p, the proportion of defective handles in the shipment, with a margin of error of 0.13 or less? I have a formula for the critical value of 95% (confidence level to be assumed), margin of error (given), n and p. I am missing both n and p but the formula states to use .05 for p when it is not given. Is this correct?