Answer:
15 y 8
Step-by-step explanation:
y = x - 7
x² + y² = 289
sustituir: x² + (x - 7)² = 289
distribuir: x² + x² - 14x + 49 = 289
sustraer + simplificar: 2x² - 14x - 240 = 0
dividir: x² - 7x - 120 = 0
x² - 15x + 8x - 120 = 0
(x - 15)(x + 8) = 0
x = 15, x = -8 --> x ≠ -8 porque -8 no es naturales
sustituir: y = 15 - 7
simplificar: y = 8
Answer:
Area = pi r squared
Step-by-step explanation:
If you need to, sometimes your teacher will ask you to leave you answers in terms of pi, or keep pi as 3.
Answer:
3/20
Step-by-step explanation:
She chose 3 songs out of twenty so those three songs should be out of that twenty.
Answer:
Um i'ma just guess i'm not really good at math even if i'm in honors so i think its D i believe
Step-by-step explanation:
Answer:
A sample of 997 is needed.
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.
In which
z is the z-score that has a p-value of
.
The margin of error is of:
![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)
A previous study indicates that the proportion of left-handed golfers is 8%.
This means that ![\pi = 0.08](https://tex.z-dn.net/?f=%5Cpi%20%3D%200.08)
98% confidence level
So
, z is the value of Z that has a p-value of
, so
.
How large a sample is needed in order to be 98% confident that the sample proportion will not differ from the true proportion by more than 2%?
This is n for which M = 0.02. 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)
![0.02 = 2.327\sqrt{\frac{0.08*0.92}{n}}](https://tex.z-dn.net/?f=0.02%20%3D%202.327%5Csqrt%7B%5Cfrac%7B0.08%2A0.92%7D%7Bn%7D%7D)
![0.02\sqrt{n} = 2.327\sqrt{0.08*0.92}](https://tex.z-dn.net/?f=0.02%5Csqrt%7Bn%7D%20%3D%202.327%5Csqrt%7B0.08%2A0.92%7D)
![\sqrt{n} = \frac{2.327\sqrt{0.08*0.92}}{0.02}](https://tex.z-dn.net/?f=%5Csqrt%7Bn%7D%20%3D%20%5Cfrac%7B2.327%5Csqrt%7B0.08%2A0.92%7D%7D%7B0.02%7D)
![(\sqrt{n})^2 = (\frac{2.327\sqrt{0.08*0.92}}{0.02})^2](https://tex.z-dn.net/?f=%28%5Csqrt%7Bn%7D%29%5E2%20%3D%20%28%5Cfrac%7B2.327%5Csqrt%7B0.08%2A0.92%7D%7D%7B0.02%7D%29%5E2)
![n = 996.3](https://tex.z-dn.net/?f=n%20%3D%20996.3)
Rounding up:
A sample of 997 is needed.