Answer:
The lowest mark should be 5.
Step-by-step explanation:
If the modal score is 11 and there are three marks we're comparing, that means 11 must appear twice as a score. To get a mean/average of 9 from three scores, all the scores must add up to 27. 11+11=22, so the final mark should be 5.
11+11+5=27
27/3=9
