Answer:
Final mean value = 24.
Mean value decreased by 6 finally.
Step-by-step explanation:
Total number of restaurant initially = 4
Mean number of tables in restaurants = 30
So, total number of tables in restaurants = 4×30 = 120
Now,
He buys 2 new restaurants with 15 tables and 9 tables .
So, final number of tables = 120 + 15 + 9 = 144.
And, final number of restaurants = 4 initially + 2 newly added = 6 restaurants.
Thus , final mean value of tables in restaurants =
= 24.
Thus , mean value decreased by 6 finally