Draw a diagram as shown below.
The diagonals are equal in length. Because AB || DC and AD || BC, the quadrilateral is a square.
Because the diagonals bisect each other at O, therefore
DO = BO = 10.
Likewise,
AO = CO = 10
Because AB = 13, therefore DC = 13.
The perimeter of ΔCOD is CO + CD + DO = 10 + 13 + 10 = 33 in
Answer: 33 in
Answer:

Now we can find the second moment with this formula:

And replacing we got:

The variance would be given by:
![Var(X) =E(X^2) -[E(X)]^2 = 21.4 -[3.8]^2 = 6.96](https://tex.z-dn.net/?f=%20Var%28X%29%20%3DE%28X%5E2%29%20-%5BE%28X%29%5D%5E2%20%3D%2021.4%20-%5B3.8%5D%5E2%20%3D%206.96)
And the deviation would be:

Step-by-step explanation:
For this case we have the following distribution given:
X 1 2 7
P(X) 1/5 2/5 2/5
We need to begin finding the mean with this formula:

And replacing we got:

Now we can find the second moment with this formula:

And replacing we got:

The variance would be given by:
![Var(X) =E(X^2) -[E(X)]^2 = 21.4 -[3.8]^2 = 6.96](https://tex.z-dn.net/?f=%20Var%28X%29%20%3DE%28X%5E2%29%20-%5BE%28X%29%5D%5E2%20%3D%2021.4%20-%5B3.8%5D%5E2%20%3D%206.96)
And the deviation would be:

Divide 400 by 10 and you will get 40. It's not hard
Answer:
a. 4 sets of tires in a year.
b. 17 times a year.
Step-by-step explanation:
a. I just divided 160,000 by 40,000 to get 4 sets a year.
b. I divided 160,000 by 10,000 and then added 1 to get 17 times a year. I added one because the problem said that the trucker changes the oil in the beginning of the year.