Solve:
Do the parenthesis first, so 4*9=36
Now multiply it by 1.
1*36=36
Final answer: 36
Calculate the circumference of the full circle:
circumference = PI x diameter = 3.14 x 20 = 62.8 inches
the arc length is 160 degrees of the full circle
divide 160 by 360 (full circle) and multiply by the circumference:
160/360 x 62.8 = 27.9 inches
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.
Answer and Step-by-step explanation:
a)
expected value for the difference in sample means=3.5-3.2=0.3
b)
standard deviation of the sampling distribution of the difference in sample means
=sqrt((0.5^2/40)+(0.8^2/40))
=0.1492
c)
z=(0.3-0)/0.1492
z=2.01
P(z>2.01)=0.0222
Your answer is c
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Hope this helped you :)
