Answer:
The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is between 49.34% and 60.66%, which means that we are 99% sure that the true percentage of US adult Twitter users who get some news is in this interval.
Step-by-step explanation:
Confidence interval:
A confidence interval has the following format:
![M \pm zs](https://tex.z-dn.net/?f=M%20%5Cpm%20zs)
In which M is the sample mean, z is related to the confidence level and s is the standard error.
55% of U.S. adult Twitter users get at least some news on Twitter (Pew, 2013). The standard error for this estimate was 2.2%.
This means that ![M = 55, s = 2.2](https://tex.z-dn.net/?f=M%20%3D%2055%2C%20s%20%3D%202.2)
99% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Lower bound of the interval:
Upper bound:
The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is between 49.34% and 60.66%, which means that we are 99% sure that the true percentage of US adult Twitter users who get some news is in this interval.
Answer:
b MAYBE don't pink thou swy
Answer:
A
Step-by-step explanation:
x-8
last week-this week
4x+18=7x-12
We move all terms to the left:
4x+18-(7x-12)=0
We get rid of parentheses
4x-7x+12+18=0
We add all the numbers together, and all the variables
-3x+30=0
We move all terms containing x to the left, all other terms to the right
-3x=-30
x=-30/-3
x=+10
Hope this helps :)
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