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:
All I can tell you from what you've given me is that the slope is positive, and the y-intercept is 1.
Step-by-step explanation:
<em>Hope </em><em>I</em><em>t</em><em> </em><em>helps!</em>
Answer:(2,0) x=2,y=0
Step-by-step explanation:
Let's solve your system by elimination.
−x+y=−2;2x−3y=4
Multiply the first equation by 2,and multiply the second equation by 1.
2(−x+y=−2)
1(2x−3y=4)
Becomes:
−2x+2y=−4
2x−3y=4
Add these equations to eliminate x:
−y=0
Then solve−y=0 for y:
−y=0
−y/−1 =0/−1
(Divide both sides by -1)
y=0
Now that we've found y let's plug it back in to solve for x.
Write down an original equation:
−x+y=−2
Substitute0foryin−x+y=−2:
−x+0=−2
−x=−2(Simplify both sides of the equation)
−x/−1 = −2/−1
(Divide both sides by -1)
x=2
Answer:
Hope this helps
Step-by-step explanation:
x = 16
It would be B. because it's just 7 times 1.5