Respuesta :

Order.

9, 12, 12, 14, 15, 16, 18, 21

Now split into quarters.

9, 12, 12, 14, 15, 16, 18, 21
          |          |           |
        (1)                   (3)

Determine the values of (1) and (3) by using medians.

14 + 12 + 12 + 9 / 4
47 / 4
approx. 12

So Q1 = 12.

15 + 16 + 18 + 21 / 4
70 / 4
approx. 17

Therefore the answer is C I think. I have not done this ever before. All the knowledge I did was from research lol