Answer: The vertex of the parabola (quadratic function) is (-2,-4)
Fourth option: (-2,-4)
Solution:
y=x^2+4x
y=ax^2+bx+c; a=1, b=4, c=0
Vertex: V=(h,k)
h=-b/(2a)
h=-4/(2(1))
h=-4/2
h=-2
y=x^2+4x
k=y=h^2+4h
k=(-2)^2+4(-2)
k=4-8
k=-4
Vertex: V=(h,k)
Vertex: V=( -2, -4)
The mean is the average of a set of numbers.
To find the mean of this data, form a number set by gathering all the numbers.
We need to find the average weekly allowance. To do this, each number in the number set should be the different allowances, and their quantity is the number of students who earned that allowance.
In this case, there would be seven 0s, five 3s, seven 5s, three 6s, and two 8s.
The numbers are:
0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 3, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 8, 8
To find the mean of these numbers, add then together then divide by the total amount of numbers.
This means doing:
(0 + 0 + 0 + 0 + 0 + 0 + 0 + 3 + 3 + 3 + 3 + 3 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 6 + 6 + 6 + 8 + 8) / 7 + 5 + 7 + 3 + 2
An easier formula could be used by using multiplication.
This would be [7(0) + 5(3) + 7(5) + 3(6) + 2(8)] / 24
This is a lot easier to read!
Now to solve it.
7 • 0 = 0
5 • 3 = 15
7 • 5 = 35
3 • 6 = 18
2 • 8 = 16
0 + 15 + 35 + 18 + 16 = 84
84 / 24 = 3.5
The mean is 3.5, or $3.50
This means that the average weekly allowance amongst these students is $3.50.
Hope this helps!
If the diameter is 30 ft then the area of the circle is 706.5 you can approximate it if you want and you will have 707.
You subtract 3 miles from the 5.5 miles which gives you 2.5
