;;
;;*******************************************
;;
;;Assignment 01, Question 4
;;(Course grade manipulation)
;;
;;*******************************************
;;

(define weight-participation 0.05)
(define weight-assignments 0.2)
(define weight-midterm1 0.1)
(define weight-midterm2 0.2)
(define weight-exam 0.45)

;; final-CS135-grade: num num num num num -> num
;; Calculates your final course grade acccording to weightings.
;; Example:
;; (final-CS135-grade 100 100 100 100 100) => 100
(define (final-CS135-grade participation assignments midterm1 midterm2 exam)
  (+ (* participation weight-participation) (* assignments weight-assignments) (* midterm1 weight-midterm1) (* midterm2 weight-midterm2) (* exam weight-exam)))

;; final-exam-grade-needed-CS135: num num num num num -> num
;; Returns the mark needed on the final exam to acheive the desired final mark for the course
;; Example:
;; (final-CS135-grade 50 50 50 50 70) => 94.4
(define (final-exam-grade-needed-CS135 participation assignments midterm1 midterm2 desiredfinal)
  (/ (- desiredfinal (* participation weight-participation) (* assignments weight-assignments) (* midterm1 weight-midterm1) (* midterm2 weight-midterm2)) weight-exam))