Answer:
a). The mean = 1000
      The variance = 999,000
      The standard deviation = 999.4999
b). 1000 times , loss
Step-by-step explanation:
The mean of geometric distribution is given as , 
And the variance is given by, 
Given : 
              = 0.001
The formulae of mean and variance are :



a). Mean =   
               =  
 
               = 1000
   Variance =   
                   = 
                            = 999,000
    The standard deviation is determined by the root of the variance.
     
         =  = 999.4999
 = 999.4999
b). We expect to have play lottery 1000  times to win, because the mean in part (a) is 1000. 
When we win the profit is 500 - 1 = 499
 When we lose, the profit is -1
Expected value of the mean μ is the summation of a product of each of the possibility x with the probability P(x).

   = $ 0.50
Since the answer is negative, we are expected to make a loss.
 
        
             
        
        
        
The picture with the complete question is attached below :
Answer:
In Step 2, 90 should be multiplied by the quantity 10 – 12, not by 10
Step-by-step explanation:
90 * x - 90 * 12 = 90(x - 12)
From the question, x = 10
Hence, 
90(10 - 12) 
(90* 10) - (90 * 12) - - - > correct evaluation
900 - 1080
= - 180
Hence, both values in the bracket, that is 10 and - 12 should be multiplied by 90. Not just 10 alone. 
 
        
             
        
        
        
Answer:
Everything except 21/40. That is your ratio. The denominator always 
 
        
             
        
        
        
<span>Bob says he has 3 kids, the product of their age is 72.
So the possible ages of Bob's kids can be taken from the factors of 72
72 = 2 * 2 * 2 * 3 * 3
</span><span>Finally, bob says, my youngest child called justice.
</span>So meaning, Bob has a youngest child. He didn't mention about a twin.
So the possible ages the following:
1, 2, 36 --> sum: 39
1, 4, 18 --> sum: 23
1, 8, 9 --> sum: 18
<span>Once the sum of the ages will be revealed, then the possible ages are mentioned above.</span>