Answer:
The 95% confidence interval for the population mean is between 17.93 days and 24.07 days.
Step-by-step explanation:
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 sample mean subtracted by M. So it is 21 - 3.07 = 17.93 days
The upper end of the interval is the sample mean added to M. So it is 21 + 3.07 = 24.07 days
The 95% confidence interval for the population mean is between 17.93 days and 24.07 days.
A square is made up of 4 equal sides all you would have to do to find the perimeter is divided 86 by 4 and that equals 21.5
21.5 should be your answer
The confidence interval is given by the formula:
m +/- z·(σ/√n)
First, compute the mean:
m = (<span>15.8 + 15.6 + 15.1 + 15.2 + 15.1 + 15.5 + 15.9 + 15.5) / 8
= 15.463
Then, compute the standard deviation:
</span>σ = √[∑(v - m)²/n]
= 0.287
The z-score for a 95% confidence interval is z = 1.96.
Now you can calculate:
m + z·(σ/√n) = 15.463 + 1.96·(0.287/√8)
= 15.463 + 0.199
= 15.662
m - z·(σ/√n) = 15.463 - 1.96·(0.287/√8)
= 15.463 - 0.199
= 15.264
Therefore the confidence interval is (15.264, <span>15.662) and the correct answer is E) none of the above.</span>
Answer: x = 6, the y - coordinate is 4, therefore the value of the function when x = 6 is 4.
