Please help me answer these questions with full solutions and steps in HYPOTHESIS TESTING, I will give 5 stars

3. Medical literatures tell us that our blood is mainly composed of red and white corpuscles and a normal body must average 7250/mm3 of white blood cell counts. If a sample of 15 individuals chosen at random from a certain place have an average of 485o/mm3 with a standard deviation of 2500/mm3, would you say that the people in that place have low white blood cell count? Test at 5% level of significance. 4. The manager ofthe car rental agency claims that the average mileage of cars rented is less than 8000 km. A sample of 5 cars has an average mileage 0f7723 km with a standard deviation of 500 km. At 0L=o.05, is there enough evidence to reject the manger's claim