Answer:
diameter = 2.5 feet
Step-by-step explanation:
Circumference of a circle is given as C = πd
Circumference of the tree trunk = 7.85 ft
π = 3.14
Diameter of the tree trunk = d
Thus:
7.85 = 3.14*d
Divide both sides by 3.14
7.85/3.14 = 3.14*d/3.14
2.5 = d
d = 2.5 ft
Answer:
13
Step-by-step explanation:
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: The common ratio is -1/3
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Work Shown:
Pick any term to divide it by the previous term. I'm going to pick the second term and divide it by the first term.
r = common ratio
r = (term 2) divided by (term 1)
r = (4/9) divided by (-4/3)
r = (4/9) * (-3/4)
r = (4*(-3))/(9*4)
r = -12/36
r = -1/3
The common ratio is -1/3
This means you multiply each term by -1/3 to get the next term
For instance
term 2 = r*(term 1)
term 2 = (-1/3)*(-4/3)
term 2 = ((-1)*(-4))/(3*3)
term 2 = 4/9