Subject MJ Katie Sherwin Class mean Class standard deviation English 50 60 85 60 10 Computers 63 70 72 65 5 Mathematics 65 60 55 55 151. MJ, Katie and Sherwin are part of a large class that sat for an end of semester examination in En glish, Computers and Mathematics. The marks in these examinations were approximately normally distributed. Each exam had a maximum mark of 100. The results for these students are given in the following table1 together with class means and standard deviations. Subject MJ Katie Sherwin Class mean Class standard deviation English 50 60 85 60 10 Computers 63 70 72 65 5 Mathematics 65 60 55 55 15 (a) Convert each student's marks to z-scores. (b) Relative to the rest of the students: Which is MJ's worst result? Did MJ get a better result in Computers or Mathematics? (0) Which is better: MJ's mark in Mathematics or Katie's mark in Computers? (d) Standardise all the marks to a mean of 50 and a standard deviation of 15. Add each student's standardised marks to give them an \"aggregate\" or total mark out of 300. Which student had the best \"aggregate\