Answer:
The 95% confidence interval for μ for the given situation is between 87.49 and 94.51.
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.

The lower end of the interval is the sample mean subtracted by M. So it is 91 - 3.51 = 87.49
The upper end of the interval is the sample mean added to M. So it is 91 + 3.51 = 94.51
The 95% confidence interval for μ for the given situation is between 87.49 and 94.51.
<span>1.1401754250991 I used a caculator sorry ;c</span>
Answer:
6 + 2x
Step-by-step explanation:
Answer:
x = - 4 y = - 4
Step-by-step explanation:
x+y= - 8
-9x-6y=60
First, solve for x in the first equation:
x+y = - 8 Subtract y from both sides
x + y - y = -8 - y y cancels on the left
x = - 8 - y
Now plug in what you found for x into the 2nd equation and solve for y.
- 9x - 6y = 60
-9(- 8 - y) - 6y = 60 Multiply out
72 + 9y - 6y = 60
72 + 3y = 60 Subtract 72 from both sides
72 - 72 + 3y = 60 - 72 72 cancels on the left
3y = - 12 Divie both sides by 3
3y/3 = -12/3 3 cancels on the left because 3/3 = 1
y = -4
Now plug your answer for y back into the first equation to get x.
x + y = -8
x + (-4) = - 8 Add 4 to each side
x - 4 + 4 = - 8 + 4 4 cancels on the left
x = -4
x = - 4 and y = - 4
Step 1:
Add rent & car payments
=11,250+1422
=$12,672
Step 2:
to determine %, set up a proportion
12,672 is to his total of 39,600 as x is to 100
12,672/39,600 = x/100
cross multiply
(12,672)(100) = (39,600)(x)
1,267,200= 39,600x
divide both sides by 39,600
32%= x
OR
Alternative Step 2:
12,672 ÷ 39,600= 0.32
Alternative Step 3:
0.32 x 100 = 32%
or move decimal to the right 2 places
His rent and car payments are 32% of his earnings.
Hope this helps! :)