Answer:
4π cm = 12.57 cm
Step-by-step explanation:
180 degrees is half of a circle, so the length of the arc is half of the circumference.
length = (2πr)/2 = πr = 4π cm = 12.57 cm
To get the surface area of a sphere, we need to have the radius. We are given the circumference. The circumference formula is C=2πr. We need to solve for r.
23 = 2πr
r=3.66
The calculation for surface area is <span>A = 4πr^2.
</span>A = 4<span>π(3.66)^2
Solve for A.
A= 168 cm^2.</span>
The 2 graph models cat population because as it says the cat has been with it after 6 months and it stays the same
Using the z-distribution, the test statistic is:
c) -2.63.
<h3>What are the hypothesis tested?</h3>
At the null hypothesis we test if the means are equal, equivalent to a subtraction of 0, hence:
At the alternative hypothesis, we test if they are different, hence:
<h3>What are the mean and the standard error for the distribution of differences?</h3>
For each sample, they are given as follows:
.
.
For the distribution of differences, it is given by:
.
<h3>What is the test statistic?</h3>
The test statistic is given by:
In which 
is the value tested at the null hypothesis.
Hence:
z = -2.63.
More can be learned about the z-distribution at brainly.com/question/13873630
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