Class exercise/tutorial (1) You meet with all fourth grade teachers and they propose that fourth graders this year are unusually dull and the reading achievement is low because their average verbal IQ is well below the national average (National mean =100, o = 15). Test whether fourth grade teachers assumption is true or not at 5% significant level. Sampling of 400 fourth graders yield the following; X = 98, s = 15. What is your conclusion