6.(1+1+1 =3 marks) Alex and Boris are taking college preparatory exams. Boris writes the ACT test and scores 15 out of 30. Alex writes SAT test, and scores 1125 out of 1600. If the means and standard deviations of scores for the ACT test are 25 and 5, and for the SAT test are 1150 and 50, then a. Alex's z -score is : b. Boris z-score is : c. Write proper names above the lines below: performed on exam better than You are not required to show your work necessary to state the answers for all the questions