So... our numbers... let's say the first one is hmmm "a"
so the second and subsequent are
a
a+1
a+2
a+3
a+4
there, 5 consecutive whole numbers or integers for that matter
now, we know the sum of the square of the first three,
is the same as the sum of the square of the last two
so
![\bf \begin{cases} a\\ a+1\\ a+2\\ \textendash\textendash\textendash\textendash\\ a+3\\ a+4 \end{cases}\qquad (a)^2+(a+1)^2+(a+2)^2=(a+3)^2+(a+4)^2](https://tex.z-dn.net/?f=%5Cbf%20%5Cbegin%7Bcases%7D%0Aa%5C%5C%0Aa%2B1%5C%5C%0Aa%2B2%5C%5C%0A%5Ctextendash%5Ctextendash%5Ctextendash%5Ctextendash%5C%5C%0Aa%2B3%5C%5C%0Aa%2B4%0A%5Cend%7Bcases%7D%5Cqquad%20%28a%29%5E2%2B%28a%2B1%29%5E2%2B%28a%2B2%29%5E2%3D%28a%2B3%29%5E2%2B%28a%2B4%29%5E2)
do a binomial theorem expansion on those, solve for "a"
Answer:
We need a sample size of 564.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
![\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}](https://tex.z-dn.net/?f=%5Cpi%20%5Cpm%20z%5Csqrt%7B%5Cfrac%7B%5Cpi%281-%5Cpi%29%7D%7Bn%7D%7D)
In which
z is the zscore that has a pvalue of
.
For this problem, we have that:
![\pi = \frac{81}{130} = 0.6231](https://tex.z-dn.net/?f=%5Cpi%20%3D%20%5Cfrac%7B81%7D%7B130%7D%20%3D%200.6231)
The margin of error is:
![M = z\sqrt{\frac{\pi(1-\pi)}{n}}](https://tex.z-dn.net/?f=M%20%3D%20z%5Csqrt%7B%5Cfrac%7B%5Cpi%281-%5Cpi%29%7D%7Bn%7D%7D)
95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Based upon a 95% confidence interval with a desired margin of error of .04, determine a sample size for restaurants that earn less than $50,000 last year.
We need a sample size of n
n is found when ![M = 0.04](https://tex.z-dn.net/?f=M%20%3D%200.04)
So
![M = z\sqrt{\frac{\pi(1-\pi)}{n}}](https://tex.z-dn.net/?f=M%20%3D%20z%5Csqrt%7B%5Cfrac%7B%5Cpi%281-%5Cpi%29%7D%7Bn%7D%7D)
![0.04 = 1.96\sqrt{\frac{0.6231*0.3769}{n}}](https://tex.z-dn.net/?f=0.04%20%3D%201.96%5Csqrt%7B%5Cfrac%7B0.6231%2A0.3769%7D%7Bn%7D%7D)
![0.04\sqrt{n} = 1.96\sqrt{0.6231*0.3769}](https://tex.z-dn.net/?f=0.04%5Csqrt%7Bn%7D%20%3D%201.96%5Csqrt%7B0.6231%2A0.3769%7D)
![\sqrt{n} = \frac{1.96\sqrt{0.6231*0.3769}}{0.04}](https://tex.z-dn.net/?f=%5Csqrt%7Bn%7D%20%3D%20%5Cfrac%7B1.96%5Csqrt%7B0.6231%2A0.3769%7D%7D%7B0.04%7D)
![(\sqrt{n})^{2} = (\frac{1.96\sqrt{0.6231*0.3769}}{0.04})^{2}](https://tex.z-dn.net/?f=%28%5Csqrt%7Bn%7D%29%5E%7B2%7D%20%3D%20%28%5Cfrac%7B1.96%5Csqrt%7B0.6231%2A0.3769%7D%7D%7B0.04%7D%29%5E%7B2%7D)
![n = 563.8](https://tex.z-dn.net/?f=n%20%3D%20563.8)
Rounding up
We need a sample size of 564.
Answer:
$2.25
Step-by-step explanation:
You can find the answer by setting up a simple equation.
Brand X is 1.65 for 11 ounces
we can find the cost of one ounce of Brand X by using division
1.65/11
.15
this means that for every ounce of Brand X, it costs 15 cents
Since brand Y costs two cents more per ounce that would make it be 17 cents per ounce
now all you need to do is multiply and solve.
.15 * 15 = $2.25
The area of the frame would be 19.25’