Use the price-demand function below, to answer parts (A), (B), and (C).
p(x) = 9- 3x 1< x < 20
(A) what is the revenue function?
r(x)=
what is the domain of the revenue function?
multiple question
a.0,672
b.1,20
c.0,20
d.0,90
Answer:
The sample must be of at least 48 pizzas.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
![\alpha = \frac{1-0.9}{2} = 0.05](https://tex.z-dn.net/?f=%5Calpha%20%3D%20%5Cfrac%7B1-0.9%7D%7B2%7D%20%3D%200.05)
Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so ![z = 1.645](https://tex.z-dn.net/?f=z%20%3D%201.645)
Now, find the margin of error M as such
![M = z*\frac{\sigma}{\sqrt{n}}](https://tex.z-dn.net/?f=M%20%3D%20z%2A%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D)
In which
is the standard deviation of the population and n is the size of the sample.
How large a sample must she take if she wants the margin of error to be under 0.5 inch?
She needs a sample of at least n, in which is found when ![M = 0.5, \sigma = 2.1](https://tex.z-dn.net/?f=M%20%3D%200.5%2C%20%5Csigma%20%3D%202.1)
![M = z*\frac{\sigma}{\sqrt{n}}](https://tex.z-dn.net/?f=M%20%3D%20z%2A%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D)
![0.5 = 1.645*\frac{2.1}{\sqrt{n}}](https://tex.z-dn.net/?f=0.5%20%3D%201.645%2A%5Cfrac%7B2.1%7D%7B%5Csqrt%7Bn%7D%7D)
![0.5\sqrt{n} = 2.1*1.645](https://tex.z-dn.net/?f=0.5%5Csqrt%7Bn%7D%20%3D%202.1%2A1.645)
![\sqrt{n} = \frac{2.1*1.645}{0.5}](https://tex.z-dn.net/?f=%5Csqrt%7Bn%7D%20%3D%20%5Cfrac%7B2.1%2A1.645%7D%7B0.5%7D)
![(\sqrt{n})^{2} = (\frac{2.1*1.645}{0.5})^{2}](https://tex.z-dn.net/?f=%28%5Csqrt%7Bn%7D%29%5E%7B2%7D%20%3D%20%28%5Cfrac%7B2.1%2A1.645%7D%7B0.5%7D%29%5E%7B2%7D)
![n = 47.73](https://tex.z-dn.net/?f=n%20%3D%2047.73)
Rounding up
The sample must be of at least 48 pizzas.
Answer:
I'm not completely sure but I beileve Jackie less than 4
Step-by-step explanation:
good luck tho
I hope my answer is right
To get the the cost of how much Alexis is paying we first have to find the original cost and then subtract the $15 which is equal to 20% of the original number.
To find the original price you take the $15 and divide it by .20
15÷.20= 75
To get the original price of a percentage you do the opposite of if you were trying to find the % for example :
75 x .20 = 15
15 ÷ .20 =75
The original price is $75
75 - 15 = 60
With the discount it is $60
I hope it helped