Answer to Question #91522 in Statistics and Probability for Dinao

Question

To obtain Grade A, Ben must achieve an average of at least 70 in five tests. If his average mark the first four test is 68, what is the lowest he can get in his fifth test and still obtain Grade A?

Answer 1

To obtain Grade A Ben must have sum in five tests at least 350 (then average will be at least 70). 4 * 68 = 272 - total marks in first four tests. So he must get in fifth test 350 - 272 = 78 to obtain grade A

Answer: 78