Using the z-distribution, as we are working with a proportion, it is found that the 99% confidence interval for the proportion of all U. S. Adults who would include the 9/11 attacks on their list of 10 historic events is (0.7458, 0.7942). It means that we are 99% sure that the true proportion for all U.S. adults is between these two bounds.
<h3>What is a confidence interval of proportions?</h3>
A confidence interval of proportions is given by:

In which:
is the sample proportion.
In this problem, the parameters are:

The lower limit of this interval is:

The upper limit of this interval is:

The 99% confidence interval for the proportion of all U. S. Adults who would include the 9/11 attacks on their list of 10 historic events is (0.7458, 0.7942). It means that we are 99% sure that the true proportion for all U.S. adults is between these two bounds.
More can be learned about the z-distribution at brainly.com/question/25890103
Answer:
y = 24
Step-by-step explanation:
8 : 4 : : y : 48
8 / 4 = y / 48
1 / 2 = y / 48
y = 48 / 2
y = 24
Answer:
-cos^4(x)
Step-by-step explanation:
Step 1: Use the Pythagorean identity : 1=cos^2(x) + sin^2(x)
1-sin^2(x) = cos^2(x)
-1+sin^2(x) = -cos^2(x)
cos^2(x) (-cos^2(x))
Step 2: Factor out common terms cos^2(x)
cos^2(x) (sin^2(x)-1)
Ans: -cos^4(x)
When you say "which," it sounds like it should be multiple choice. Anyways, here's the simplified form of


(When simplifying fractions, you should <em>never</em> have a square root on the bottom. Multiply by the square root to cancel it out)