You have a score of X 65 on an exam Which set of parameters

You have a score of X = 65 on an exam. Which set of parameters would give you the best grade on the exam?       

       = 60 and = 10
       = 60 and = 5
       = 70 and = 10
       = 70 and = 5

Solution

You have a score of X = 65 on an exam. Which set of parameters would give you the best grade on the exam?       

       = 60 and = 10
       = 60 and = 5
       = 70 and = 10
       = 70 and = 5

Answer        = 60 and = 5 this has large z score of 1

z=(65-60)/10 =0.5

z=(65-60)/5 =1    

z=(65-70)/10 =-0.5

z=(65-70)/5 =-1