Answer:
Step-by-step explanation:
Range goes from the lowest point on a graph to the highest point, not including anything in between those 2 extremes. We will evaluate the quadratic for the values given. First f(2):
so
f(2) = -1
Now, f(4):
so
f(4) = 11
Now, f(7):
so
f(7) = 44
The lowest y value is -1 and the highest is 44, so the range is from -1 to 44 (I can't tell which of your choices reflects that because it's too small!)
Here is our profit as a function of # of posters
p(x) =-10x² + 200x - 250
Here is our price per poster, as a function of the # of posters:
pr(x) = 20 - x
Since we want to find the optimum price and # of posters, let's plug our price function into our profit function, to find the optimum x, and then use that to find the optimum price:
p(x) = -10 (20-x)² + 200 (20 - x) - 250
p(x) = -10 (400 -40x + x²) + 4000 - 200x - 250
Take a look at our profit function. It is a normal trinomial square, with a negative sign on the squared term. This means the curve is a downward facing parabola, so our profit maximum will be the top of the curve.
By taking the derivative, we can find where p'(x) = 0 (where the slope of p(x) equals 0), to see where the top of profit function is.
p(x) = -4000 +400x -10x² + 4000 -200x -250
p'(x) = 400 - 20x -200
0 = 200 - 20x
20x = 200
x = 10
p'(x) = 0 at x=10. This is the peak of our profit function. To find the price per poster, plug x=10 into our price function:
price = 20 - x
price = 10
Now plug x=10 into our original profit function in order to find our maximum profit:
<span>p(x)= -10x^2 +200x -250
p(x) = -10 (10)</span>² +200 (10) - 250
<span>p(x) = -1000 + 2000 - 250
p(x) = 750
Correct answer is C)</span>
We can subtract the acres of corn from the acres of wheat.
She planted 3 1/4 more acres of wheat than corn.
The coefficient of determination can be found using the following formula:
![r^2=\mleft(\frac{n(\sum ^{}_{}xy)-(\sum ^{}_{}x)(\sum ^{}_{}y)}{\sqrt[]{(n\sum ^{}_{}x^2-(\sum ^{}_{}x)^2)(n\sum ^{}_{}y^2-(\sum ^{}_{}y)^2}^{}}\mright)^2](https://tex.z-dn.net/?f=r%5E2%3D%5Cmleft%28%5Cfrac%7Bn%28%5Csum%20%5E%7B%7D_%7B%7Dxy%29-%28%5Csum%20%5E%7B%7D_%7B%7Dx%29%28%5Csum%20%5E%7B%7D_%7B%7Dy%29%7D%7B%5Csqrt%5B%5D%7B%28n%5Csum%20%5E%7B%7D_%7B%7Dx%5E2-%28%5Csum%20%5E%7B%7D_%7B%7Dx%29%5E2%29%28n%5Csum%20%5E%7B%7D_%7B%7Dy%5E2-%28%5Csum%20%5E%7B%7D_%7B%7Dy%29%5E2%7D%5E%7B%7D%7D%5Cmright%29%5E2)
Using a Statistics calculator or an online tool to work with the data we were given, we get
So the best aproximation of r² is 0.861
You simply multiply all the options
3x2x3= 18 possibilities
