Answer:a
Step-by-step explanation:
A principle square root of a real number that's not negative, such as 49,
is the square root of that number that is not negative.If you take the square root of 49, you get either -7 or 7, since both

and

equal 49. However, the principle square root would be
A) 7, since it's not negative.
-3 will be your slope and your y-intercept will be -2... equation i: y=-3x-2
It's 300 because you divide 60 by 12 which gives you 5, then multiply 60 and 5.
Answer:
a
The average cost is 
b
The standard deviation of cost is
Step-by-step explanation:
From the question we are told that




The cost of replacing the two component is C = 50 + 2 X + 4 Y
The variance of X is mathematically represented as
V(X) =
Substituting values
![V[X] = 24 - 4^2](https://tex.z-dn.net/?f=V%5BX%5D%20%3D%20%2024%20-%204%5E2)
![V[X] =8](https://tex.z-dn.net/?f=V%5BX%5D%20%3D8)
The variance of Y is mathematically represented as
V(Y) =
Substituting values
![V[Y] = 8 - 2^2](https://tex.z-dn.net/?f=V%5BY%5D%20%3D%20%208%20-%202%5E2)
![V[X] =4](https://tex.z-dn.net/?f=V%5BX%5D%20%3D4)
The average of replacing the two component is

substituting value


The variance of replacing the two component is
Note: The variance of constant is zero
and X and Y are independent
=> 
substituting values
=>
=>
=> 
The standard deviation is
substituting values