1 and 8 should be the answer I believe.
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
Angle 4 would be 77degrees because angle two is vertical to angle four.
Angle 3 and Angle 1 are equal because they are vertical to each other.
You would subtract 180 (degrees) minus 77 (degrees) and get 103 (degrees).
So Angle 3 and Angle 1 would both be 103 degrees.
You would get 180 degrees from the line.
Answer: 2 radians
Step-by-step explanation: You welcome