Answer:
The correct answer is OB.
Step-by-step explanation:
Let us recall the Associative Property of Addition: given three real numbers ,
and
the following equality holds:
.
Let us remark that the Associative Property of Addition tells us that we can perform the sums in any order. So,
.
In the other options there was used the Commutative Property of Addition.
Answer:
The margin of error for a 99% confidence interval for the population mean is 1.8025.
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 the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
In this problem:
So
The margin of error for a 99% confidence interval for the population mean is 1.8025.