someone please help me!
GIVING BRAINLIST TO FIRST RIGHT ANSWER

Answer:
A. The mean is increased by 3
Step-by-step explanation:
2 + 9 + 11 + 10 + 3 + 5 + 4 + 12 = 56/8 = 7
2 + 9 + 11 + 10 + 3 + 5 + 4 + 12 + 34 = 90/9 = 10
10 - 7 = 3