Create a method get_grade that accepts an Array of test scores. Each score in the array should be between 0 and 100, where 100 is the max score. Compute the average score and return the letter grade as a String, i.e., 'A', 'B', 'C', 'D', 'E', or 'F'. For example, # How studious! get_grade([100, 100, 100]) # => 'A'

Calculate the letter grade of a series of grades

def get_grade(test_scores)
  x = test_scores.inject{|sum,x| sum + x } #sum of all test scores
  y = x/test_scores.length #divide by number of test scores
  
  if y >= 90
    return "A"
  elsif y >=80
    return "B"
  elsif y>= 70
    return "C"
  elsif y>=60
    return "D"
  elsif y <60
    return "F"
  end
  
end

test_scores = [70, 65, 99, 83]