Answer:
a.1.90 years
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 question:

So

So the correct answer is:
a.1.90 years
Answer:
The answer is (4,2)
Step-by-step explanation:
in the point (-4,5) X=-4 AND Y=5
so if you move 8 units right, the X increases by 8(because the the x axis is left and right) so X transform into 4= -4+8=4
With Y(the y axis is up and down) whe u go 3 units down un decrease the number so Y transforms into 2== 5-3=2
The new coordiantes are(4,2)