15 is the answer it is correct can
The should be 158 ways, because 9*8+8*7+6*5=158.
Answer:
There are 84 total boats.
Step-by-step explanation:
In order to find this, we first need to find the fraction which are red. We can do this by multiplying the whole by how many are not white.
1 * 1/4 = 1/4
Now we take that amount and multiply it by the amount that are not blue of the remaining.
1/4 * 3/7 = 3/28
Now that we have this, and we know this is 9 boats, we can divide 9 by this fraction and it will give us the total number of boats.
9 ÷ 3/28 = 84
To compare the two classes, the Coefficient of Variation (COV) can be used. The formula for COV is this:
C = s / x
where s is the standard deviation and x is the mean
For the first class:
C1 = 10.2 / 75.5
C1 = 0.1351 (13.51%)
For the second class:
C2 = 22.5 / 75.5
C2 = 0.2980 (29.80%)
The COV is a test of homogeneity. Looking at the values, the first class has more students having a grade closer to the average than the second class.
