to ensure bills are paid on time in a hospital, a nurse will call each patient to remind the payment. as a result, only 60% of patients receive such...

to ensure bills are paid on time in a hospital, a nurse will call each patient to remind the payment. as a result, only 60% of patients receive such a call. of the patients called, 90% paid on time, while only 30% of those not called pay on time. the hospital just received a payment from a patient, what is the probability that the nurse did not call this patient?