A company that receives shipments of batteries tests a random sample of nine of them before agree

A community that receives shipments of batteries experiences a casual specimen of nine of them antecedently coincident to assume a shipment. The community is disturbed that the penny average offspring for all batteries in the shipment should be at last 50 hours. From departed experience it is unendangered to terminate that the population arrangement of offsprings is usual after a while a banner derangement of 3 hours. For one detail shipment the average offspring for a specimen of nine batteries was 48.2 hours.a. Test, at the 10% raze, the inoperative theory that the population average offspring is at last 50 hours.b. Find the capacity of a 10%-raze experience when the penny average offspring of batteries is 49 hours.