Answer:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
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:
![n = 500, \pi = \frac{421}{500} = 0.842](https://tex.z-dn.net/?f=n%20%3D%20500%2C%20%5Cpi%20%3D%20%5Cfrac%7B421%7D%7B500%7D%20%3D%200.842)
95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:
![\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.842 - 1.96\sqrt{\frac{0.842*0.158}{500}} = 0.81](https://tex.z-dn.net/?f=%5Cpi%20-%20z%5Csqrt%7B%5Cfrac%7B%5Cpi%281-%5Cpi%29%7D%7Bn%7D%7D%20%3D%200.842%20-%201.96%5Csqrt%7B%5Cfrac%7B0.842%2A0.158%7D%7B500%7D%7D%20%3D%200.81)
The upper limit of this interval is:
![\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.842 + 1.96\sqrt{\frac{0.842*0.158}{500}} = 0.874](https://tex.z-dn.net/?f=%5Cpi%20%2B%20z%5Csqrt%7B%5Cfrac%7B%5Cpi%281-%5Cpi%29%7D%7Bn%7D%7D%20%3D%200.842%20%2B%201.96%5Csqrt%7B%5Cfrac%7B0.842%2A0.158%7D%7B500%7D%7D%20%3D%200.874)
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
What ? thats very confusing what is the question you have to give more info
Answer:
x = 8
y = 6
Step-by-step explanation:
First and foremost, it's an equilateral triangle, therefore all sides and angles are equal.
Knowing that the sum of angle in a triangle is 180°, therefore each angle is 60°.
Then equating (7x+4)° to 60, we have that,
7x+4=60
7x=60-4
7x=56
x=56÷7
x=8.
Answer:
lol the answer is 49
Step-by-step explanation:
hope this helps <3