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The mean of n numbers is the sum of the numbers divided by n.
You have a mean score of 84 after taking 5 tests. Let x be the sum of scores.

You scored a total of 420 points on five tests.
You need to have a mean score of 85 after taking 6 tests. Let y be the score you need to obtain. Your total score on 6 tests is 420+y.

You need to score 90 points on the sixth test.
Step-by-step explanation:
oyasumi..................
Answer:
d
Step-by-step explanation:
the answer is d because if you do 3+2 it equals 5 so therefore it is b
Answer:
36 tiles
Step-by-step explanation:
First, find area of the square floor knowing the formula as;
Area= 
where s= side of a square.
If one side of the floor is 12 feet, then Area= 
Next, find the area of each tile using the same formula and given s=2 feet;
Area(tile) = 
To find the number of tiles needed to cover entire floor, divide area of the floor by area of one tile; 144 / 4 = 36 tiles