[Solved]Stats question regarding mean 1. The problem statement, all variables and given/known data Yo.Exam marks,X've mean 70 and standard deviation 8.7.The marks need to be scaled using the formula Y=aX+b so that the scaled marks,Y've mean 55 and standard deviation 6.96.Find the values of a and b.*From the answer sheet -to form equation for mean it's 55=70a+b,why is there "b" in there? 2. Relevant equations ? 3. The attempt at a solution 55=70a+b U don't need this,I just need some clarity on the above * thing.Pls?