Answer: D
Step-by-step explanation:
Use SOHCAHTOA
We are given the opposite of the angle and the hypotenuse. We can use the sine function to acquire the value of x°.
sin(x) = 7/13
Take the inverse sine on both sides by using a calculator to get:
x = 32.58°
Answer:
The answer would be d(c(x)) = .60x - 5
Step-by-step explanation:
In order to write an equation for d(c(x)), start with the d(y) equation.
d(y) = .80y - 5
Now input the c(x) equation in for y and then solve.
d(c(x)) = .80(.75x) - 5
d(c(x)) = .60x - 5
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:

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 
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.