Answer:
Explained below.
Step-by-step explanation:
(1)
The confidence level is, 91%.
Compute the value of α as follows:

(2)
As the population standard deviation is provided, i.e. <em>σ</em> = 256 psi, the <em>z</em> value would be appropriate.
The <em>z</em> value for α = 0.09 is,
<em>z</em> = 1.69
(3)
Compute the 91% confidence interval as follows:


(4)
The 91% confidence interval for population mean implies that there is a 0.91 probability that the true value of the mean is included in the interval, (2942.29, 3057.71) psi.
Answer: One plain roll is 4 dollars and one shiny roll is 6 dollars.
Step-by-step explanation:
lets start by saying
rolls of plain wrapping paper = x
rolls of shiny wrapping paper = y
Kathryn sold 4 plain rolls and 3 shiny rolls for 34 dollars.
4x+3y=34
Eugene sold 4 plain rolls and 2 shiny rolls for 28 dollars
4x+2y=28
Both equations will look like this.
4x+3y=34
-1(4x+2y)=(28)-1
we can multiply the second equation by -1 to get y alone. (doesn't matter which equation). Once you do that, the positive 4x and the negative 4x cancel out, 3y-2y=1y and 34-28=6. you are left with
1y=6 so one shiny roll is 6 dollars.
now use that price to find the cost of the plain roll.
lets use Kathryn's equation
4x + 3(6)=34
4x + 18= 34
-18 -18
4x=16. Divide by 4 to find cost of one plain roll.
16÷4=4. One plain roll costs 4 dollars.
Lets check. Using Kathryn's equation,
4(4) + 3(6)=34
16+18=34
34=34. We are right.
It is 9 because 11 minus 2 is equal to 9.
I need a picture of the figure otherwise i cant help
Answer:I think its ether y-interspersed or equation
Step-by-step explanation: