input: Write a python function to check if a number is in a given range.
  assert is_in_range(4, 2, 4) == True
  assert is_in_range(10, 1, 9) == False
  assert is_in_range(5, 5, 10) == True
  assert is_in_range(0, -1, 1) == True
  assert is_in_range(7, 7, 7) == True
output: def is_in_range(num, start, end):
      return start <= num <= end