Answer:
Therefore the variance on the data set is 8.3
Step-by-step explanation:
In order to find the variance of the set of data we first need to calculate the mean of the set, which is given by:
mean = sum of each element / number of elements
mean = (5 + 8 + 2 + 9 + 4)/5 = 5.6
We can now find the variance by applying the following formula:

So applying the data from the problem we have:
s² = [(5 - 5.6)² + (8 - 5.6)² + (2 - 5.6)² + (9 - 5.6)² + (4 - 5.6)²]/(5 - 1)
s² = [(-0.6)² + (2.4)² + (-3.6)² + (3.4)² + (-1.6)²]/4
s² = [0.36 + 5.76 + 12.96 + 11.56 + 2.56]/4 = 8.3
Therefore the variance on the data set is 8.3
Answer:y=-y
Step-by-step explanation:
Answer: y = -14/9(x + 4)^2 + 7
Step-by-step explanation:
The given roots of the quadratic function is (-1, -7)
The vertex is at (-4, 7)
The formula is
y = a(x - h)^2 + k
The vertex is (h, k)
Comparing with the given vertex, (-4, 7), h = -4 and k = 7
Substituting into the formula
y = a(x - h)^2 + k, it becomes
y = a(x - - 4)^2 + 7
y = a(x + 4)^2 + 7
From the roots given (-1, -7)
x = -1 and y = -7
Substituting x = -1 and y = -7 into the equation,
y = a(x + 4)^2 + 7, it becomes
-7 = a(-1+4)^2 + 7
-7 = a(3^2 ) + 7
- 7 = 9a + 7
-7-7 = 9a
9a = -14
a = -14/9
Substituting a = - 14/9 into the equation, it becomes
y = -14/9(x + 4)^2 + 7
Answer
n = 30
Explanation
To solve for n, you have to isolate it by 'getting rid' of the 18, 2, and negative sign.
You 'remove' these numbers in backward PEMDAS.
So to 'remove' the 18, you subtract both sides by 18.
3-18 = -15
-n/2+18-18 = -n/2
So now you are left with -15 = -n/2.
To 'get rid' of the 2, you multiply each side by 2.
-15×2 = -30
-n/2×2 = -n
And now you have -30 = -n.
To 'get rid' of the negative sign, you multiply both sides by -1.
-30×-1 = 30
-n×-1 = n
So you get 30 = n or n = 30.
If you still have questions I'll answer them in the comments (under this question).