The correct solution is 75.
Here !!!!!!!!!!!!!!!!!!!!
Answer:
The length of the four pieces of protective strip is 96 feet
Step-by-step explanation:
Let the w be the width of the rectangular house and L is length. Since L = w + 16, its perimeter P = 2(w + L)
= 2(w + w + 16)
= 2(2w + 16)
Since the perimeter of the house P = 136 feet,
136 = 2(2w + 16)
dividing through by 2, we have
136/2 = (2w + 16)
68 = (2w + 16)
collecting like terms, we have
68 - 16 = 2w
52 = 2w
dividing through by 2, we have
w = 52/2
w = 26 feet.
Now, since the side walk is 3 foot wide all around, the width of the house plus sidewalk = w + 3 and the length of the house plus sidewalk = L + 3 = w + 16 + 3 = w + 19.
So, the perimeter of the house plus sidewalk which is the perimeter of the four pieces of protective strip is P' = 2(w + 3 + w + 19)
= 2(w + 22)
= 2(26 + 22)
= 2(48)
= 96 feet
So, the length of the four pieces of protective strip is 96 feet.
Less than greater than equal Too
Answer:
a) 
And replacing we got:

b) ![E(80Y^2) =80[ 0^2*0.45 +1^2*0.2 +2^2*0.3 +3^2*0.05]= 148](https://tex.z-dn.net/?f=%20E%2880Y%5E2%29%20%3D80%5B%200%5E2%2A0.45%20%2B1%5E2%2A0.2%20%2B2%5E2%2A0.3%20%2B3%5E2%2A0.05%5D%3D%20148)
Step-by-step explanation:
Previous concepts
In statistics and probability analysis, the expected value "is calculated by multiplying each of the possible outcomes by the likelihood each outcome will occur and then summing all of those values".
The variance of a random variable Var(X) is the expected value of the squared deviation from the mean of X, E(X).
And the standard deviation of a random variable X is just the square root of the variance.
Solution to the problem
Part a
We have the following distribution function:
Y 0 1 2 3
P(Y) 0.45 0.2 0.3 0.05
And we can calculate the expected value with the following formula:

And replacing we got:

Part b
For this case the new expected value would be given by:

And replacing we got
![E(80Y^2) =80[ 0^2*0.45 +1^2*0.2 +2^2*0.3 +3^2*0.05]= 148](https://tex.z-dn.net/?f=%20E%2880Y%5E2%29%20%3D80%5B%200%5E2%2A0.45%20%2B1%5E2%2A0.2%20%2B2%5E2%2A0.3%20%2B3%5E2%2A0.05%5D%3D%20148)