Here’s the the answer and an explanation of how to get it :)
Answer:
The confidence interval at this level of confidence is between 5.4455 and 12.3545.
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 M as such

In which s is the standard deviation of the sample, which is also called standard error. So

The lower end of the interval is the sample mean subtracted by M. So it is 8.9 - 3.4545 = 5.4455
The upper end of the interval is the sample mean added to M. So it is 8.9 + 3.4545 = 12.3545
The confidence interval at this level of confidence is between 5.4455 and 12.3545.
Answer:
62390
Step-by-step explanation:
you have to round up if it's 5 or more and round down if it's less.
<u>Answer:</u>
a= 4
b= 8
c= 4
<u>Step-by-step explanation:</u>
<em>45-45-90 triangle </em>
x - x - 
30-60-90 triangle
x - 2x - x