Answer:
The sample mean is
b.3.55
The margin of error is
0.32
Step-by-step explanation:
Deep explanation about a confidence interval
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the mean subtracted by M. So it is 6.4 - 0.3944 = 6.01 hours.
The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 6.74 hours.
In this problem:
The deep explanation is not that important.
We just have to recognize that the interval has a lower end and an upper end. The distance from both the upper and the lower end to the mean is M. This means that the sample mean is the halfway point between the lower end and the upper end.
The margin of error is the distance of these two points(lower and upper end) to the mean.
In our interval
Lower end: 3.23
Upper end: 3.87
Sample mean

So the correct answer is:
b.3.55
The margin of error is
3.87 - 3.55 = 3.55 - 3.23 = 0.32
Answer: 75% of 6th Grade Students
Step-by-step explanation:
This sample makes the most sense because it is a majority of everyone, not just a majority of certain people. Also, Mountain School would get fewer complaints from other people if they went with a majority of 75%. Finally, running sports usually cost less then other sports.
The equation, when rewritten would be written as:
q = ( c - 54293 ) / 3.59
<h3>How to rewrite the equation in order to make q the subject</h3>
C = 3.59q + 54,293
We have the equation above, what we would have to do now would be to write the equation in such a way that q would be the subject of the formula.
This would be
3.59q = C - 54,293
Next we have to divide through by the value of q
q = 
Read more on subject of formula here: brainly.com/question/21140562
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If each pack of trail mixes is targeted to weigh 9.25 oz and must be within 0.23 oz of the target in order to be accepted, then rejected masses x, are those which weighs less than 9.02 oz or greater than 9.48 oz.
Answer:
65 degrees, because vertical angles are always congruent.
Step-by-step explanation: