Answer:
D. 31
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 
.
That is z with a pvalue of 
, so Z = 1.96.
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.
A previous study indicated that the population standard deviation is 2.8 days.
This means that 
How large a sample must be selected if the company wants to be 95% confident that the true mean differs from the sample mean by no more than 1 day?
This is n for which M = 1. So
Rounding up, at least 31 people are needed, and the correct answer is given by option D.
Hi there! ;) The answer you are looking for is 95%. To get the answer, this is what I did: 38 divided by 40 and you get 0.95 or 95% (Because they are the same value.)
Hope it helped!:D I hope this made sense to you.
i believe you can construct 2 quadrilaterals because you only need 2 right angles to make a square, once those two right angles are put together, you will now have 4 right angles. its kinda confusing but i hope this helped at all : )
The rug is 36 inches long.
