Answer:
The graph would be a line starting at one and moving to the left infinitely. The dot would be closed.
 
        
             
        
        
        
Answer:
 In order to find the variance we need to calculate first the second moment given by:
In order to find the variance we need to calculate first the second moment given by:
 And the variance is given by:
And the variance is given by:
![Var(X) = E(X^2) +[E(X)]^2 = 23.36 -[4.74]^2 = 0.8924](https://tex.z-dn.net/?f=%20Var%28X%29%20%3D%20E%28X%5E2%29%20%2B%5BE%28X%29%5D%5E2%20%3D%2023.36%20-%5B4.74%5D%5E2%20%3D%200.8924)
And the deviation would be:

Step-by-step explanation:
Previous concepts
The expected value of a random variable X is the n-th moment about zero of a probability density function f(x) if X is continuous, or the weighted average for a discrete probability distribution, if X is discrete.
The variance of a random variable X represent the spread of the possible values of the variable. The variance of X is written as Var(X).  
Solution to the problem
For this case we have the following distribution given:
X          3      4       5        6
P(X)   0.07  0.4  0.25  0.28
We can calculate the mean with the following formula:

In order to find the variance we need to calculate first the second moment given by:

And the variance is given by:
![Var(X) = E(X^2) +[E(X)]^2 = 23.36 -[4.74]^2 = 0.8924](https://tex.z-dn.net/?f=%20Var%28X%29%20%3D%20E%28X%5E2%29%20%2B%5BE%28X%29%5D%5E2%20%3D%2023.36%20-%5B4.74%5D%5E2%20%3D%200.8924)
And the deviation would be:

 
        
             
        
        
        
If you paid $14 for 600, you paid:
600 * 14 = $8,400.00
If you sold them for $15.30 a share, you made:
600 * 15.30 = $9,180
9,180 - 8,400 = $780
The return on the investment being $780
Very very safe investment and not worth it.