Answer:
B
Step-by-step explanation:
Mathematically, we shall be using the z-score here
Z-score = (x-mean)/SD
From the question, mean = 80 and SD = 4
So we want to get the option in the question that has a z-score of 1 or below
Let’s look at 75
80-75 = 5 ( this is clearly above 1 standard deviation of 4)
For 77;
80 -77 = 3
This is less than the standard deviation of 4, meaning it is within 1 standard deviation of the mean
There are 12 different ways to organize your schedule
There are 2 English classes
There are 3 math classes
There are 3 history classes
Take 2x3x3 and you get 12
15% of 30....turn ur percent to a decimal...." of " means multiply
0.15(30) = 4.5
30% of 45.....set it up the same way as before
0.30(45) = 13.5
60% of 7
0.60(7) = 4.2
23% of 20
0.23(20) = 4.6
So the ceiling takes 5/6 gallon to paint. We know that you already have 1/30 gallon and another gallon in addition to that. We must convert the 5/6 into ?/30 so we can see how much we need to use. So if we convert 5/6 to out of 30, we get 25/30. So the first can has 1/30 gallon so we subtract that amount from the total paint needed. So now we only need 24/30 gallon to paint the ceiling. If we subtract that amount needed from the full (30/30) can we have left, that will give us the remaining amount of paint we have left. 30/30-24/30= 6/30. This reduces to 1/5. So there is 1/5 gallon of paint left over after painting the ceiling.
