Answer:
The expected value of X is
and the variance of X is 
The expected value of Y is
and the variance of Y is 
Step-by-step explanation:
(a) Let X be a discrete random variable with set of possible values D and probability mass function p(x). The expected value, denoted by E(X) or
, is

The probability mass function
of X is given by

Since the bus driver is equally likely to drive any of the 4 buses, the probability mass function
of Y is given by

The expected value of X is
![E(X)=\sum_{x\in [28,32,42,44]} x\cdot p_{X}(x)](https://tex.z-dn.net/?f=E%28X%29%3D%5Csum_%7Bx%5Cin%20%5B28%2C32%2C42%2C44%5D%7D%20x%5Ccdot%20p_%7BX%7D%28x%29)

The expected value of Y is
![E(Y)=\sum_{x\in [28,32,42,44]} x\cdot p_{Y}(x)](https://tex.z-dn.net/?f=E%28Y%29%3D%5Csum_%7Bx%5Cin%20%5B28%2C32%2C42%2C44%5D%7D%20x%5Ccdot%20p_%7BY%7D%28x%29)

(b) Let X have probability mass function p(x) and expected value E(X). Then the variance of X, denoted by V(X), is
![V(X)=\sum_{x\in D} (x-\mu)^2\cdot p(x)=E(X^2)-[E(X)]^2](https://tex.z-dn.net/?f=V%28X%29%3D%5Csum_%7Bx%5Cin%20D%7D%20%28x-%5Cmu%29%5E2%5Ccdot%20p%28x%29%3DE%28X%5E2%29-%5BE%28X%29%5D%5E2)
The variance of X is
![E(X^2)=\sum_{x\in [28,32,42,44]} x^2\cdot p_{X}(x)](https://tex.z-dn.net/?f=E%28X%5E2%29%3D%5Csum_%7Bx%5Cin%20%5B28%2C32%2C42%2C44%5D%7D%20x%5E2%5Ccdot%20p_%7BX%7D%28x%29)


The variance of Y is
![E(Y^2)=\sum_{x\in [28,32,42,44]} x^2\cdot p_{Y}(x)](https://tex.z-dn.net/?f=E%28Y%5E2%29%3D%5Csum_%7Bx%5Cin%20%5B28%2C32%2C42%2C44%5D%7D%20x%5E2%5Ccdot%20p_%7BY%7D%28x%29)


Answer:
The expression has a negative rational number A as its numerical value. Positive rational B. positive integer. negative integer. Question ...
Answer: 42 cm3
Step-by-step explanation:
Answer:
The data table is attached below.
Step-by-step explanation:
The average of a set of data is the value that is a representative of the entire data set.
The formula to compute averages is:

Compute the average for drop 1 as follows:
![\bar x_{1}=\frac{1}{3}\times[10+11+9]=10](https://tex.z-dn.net/?f=%5Cbar%20x_%7B1%7D%3D%5Cfrac%7B1%7D%7B3%7D%5Ctimes%5B10%2B11%2B9%5D%3D10)
Compute the average for drop 2 as follows:
![\bar x_{2}=\frac{1}{3}\times[29+31+30]=30](https://tex.z-dn.net/?f=%5Cbar%20x_%7B2%7D%3D%5Cfrac%7B1%7D%7B3%7D%5Ctimes%5B29%2B31%2B30%5D%3D30)
Compute the average for drop 3 as follows:
![\bar x_{3}=\frac{1}{3}\times[59+58+61]=59.33](https://tex.z-dn.net/?f=%5Cbar%20x_%7B3%7D%3D%5Cfrac%7B1%7D%7B3%7D%5Ctimes%5B59%2B58%2B61%5D%3D59.33)
Compute the average for drop 4 as follows:
![\bar x_{4}=\frac{1}{3}\times[102+100+98]=100](https://tex.z-dn.net/?f=%5Cbar%20x_%7B4%7D%3D%5Cfrac%7B1%7D%7B3%7D%5Ctimes%5B102%2B100%2B98%5D%3D100)
Compute the average for drop 5 as follows:
![\bar x_{5}=\frac{1}{3}\times[122+125+127]=124.67](https://tex.z-dn.net/?f=%5Cbar%20x_%7B5%7D%3D%5Cfrac%7B1%7D%7B3%7D%5Ctimes%5B122%2B125%2B127%5D%3D124.67)
The data table is attached below.
Answer:
E = 50
D = 150
Step-by-step explanation:
We know that the exterior angle is equal to the sum of the opposite interior angles
D + E = 200
D = 3E
Substituting that into the equation
3E + E = 200
Combing terms
4E = 200
Divide by 4
4E /4 = 200/4
E = 50
D = 3E
D = 3*50 = 150