Grade Inflation

(define (american_gpa) 
  (if (flip .9) 
      (* 4 (beta 5 5)) 
      (* 4 (if (flip .8) 1 0))))

(define (indian_gpa)
  (if (flip .85) 
      (* 10 (beta 5 5)) 
      (* 10 (if (flip .7) 1 0))))

(define observed-gpa 4.0)

(define samples
  (mh-query 

   1000 10

   (define university_location 
     (if (flip .5) 'USA 'India))

   (define student_gpa 
     (if (eq? university_location 'USA) 
         (american_gpa) 
         (indian_gpa)))

   university_location

   (= (gaussian student_gpa 0.01) 
      observed-gpa)))

(hist samples)