Maybe because the diameter of the circle should equal each side length of te equilateral triangle
The answer is 0.5 when the second decimal is 5 or more you round to the next number
Answer:
Last option

Step-by-step explanation:

If we extract a sample of size n from a normal population and we want to estimate the population mean then the confidence interval for the mean will be:

Where
Where
is an estimator for the mean μ.
n is the sample size and s is its standard deviation.
is the level of significance
= 1-Confidence Level

Then 
Then the 99% confidence interval for the population mean is
