Adding another card with value $25 would decrease the standard deviation
because it is closer to the mean the the current standard deviation.
Answer:
C
Step-by-step explanation:
If x is the average (arithmetic mean) of m and 9, y is the average of 2m and 15, and z is the average of 3m and 18,
x=(m+9)/2
y=(2m+15)/2
z=(3m+18)/2
the average of x, y, and z
=(x+y+z)/3
=(m+9+2m+15+3m+18)/3
=(6m+42)/3
=2m+14
ans is C
9. 1/3+(x+20)+(x-10)+40=360 10. 1/2x+1/2x+(x-15)+(x-25)+100=540
1/3+2x+50=360 4x+60=540
(3/1) 1/3+2x=300(3/1) 4x/4=480/4
2x=300 X=120
————
2
W=150
Answer:
334 in^2.
Step-by-step explanation:
The surface area = area of the top prism + area of the bottom - 2 * area of the base of the top smaller prism
= 2(5*3 + 5*3 + 3*3) + 2(9*7 + 9*5 + 7*5) - 2* 3*5
= 2* 39 + 2*143 - 30
= 334
This is a system of equations.
First, you set everything in terms of y.
Take the first equation and move set everything equal to y
y=0+2x
Since it’s 0, you don’t need to put it, so
y=2x works.
Then, you plug y=2x into the bottom equation, for the y.
-7x +3(2x)=2. You do this because now you have the same variable for both and it can be solved easily.
Then you can simplify.
-7x+3x = 2
Then combine like terms.
-4x = 2
Divide by -4 on each side.
x = -1/2
So, now that you have x, you can plug in your x-value back into the top equation.
-2(-1/2) + y = 0
Combine like terms
1+y=0
Get y by itself
y=-1
There you have it!
You can check by plugging in both values to any of the equations. We will use the top one here.
-2(-1/2) + (-1) =0
+1 + -1 = 0
It works!
So,
X= -1/2
Y= -1
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