Answer:
C. (36337.32, 48968.68)
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
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 42653 - 6315.68 = 36337.32.
The upper end of the interval is the sample mean added to M. So it is 42653 + 6315.68 = 48968.68.
So the correct answer is:
C. (36337.32, 48968.68)
Answer:
30
Step-by-step explanation:
Do cross multiplication
<u>6</u> = <u>x</u>
18 12
Now cross multiply
(6)(12) = (18)(x)
72 = 18x
Divide both sides by 18
<u>72</u> = <u>18x</u>
18 18
4 = x
So tMei can complete 4 problems in 12 minutes.
Answer:
<u><em>x=9</em></u>.
<em><u>perimeter=68</u></em>
<em><u>area=168</u></em>
Step-by-step explanation:
First find the side that has a exact number which would be the bottom 28cm then look at the opposite side (2x+10) in order to find x subtract 10 from 28 which gives you 18, now 2x means x multiplied by 2 so what multiplied by 2 = 18? 9 meaning <u><em>x=9</em></u>. Now you are going to want to plug 9 in to your short side (x-3) once you plug it in it should look like this 9-3 and 9-3=6 meaning the short side is 6cm. In order for you to find the perimeter you have to add the sides together so 28+28+6+6 wich <u><em>=68</em></u> and in order for you to find the area you have to multiply the length and the width so 28x6 which is <em><u>168</u></em>.
hope that helped :)