1/2x + 5 = 35
You use 1/2 because she sold half of her books . Then +5 because she gained 5 back and 35 because your end total should be 35.
Hope this helps ! :)
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
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.
Doesn't play sport
Plays sport |
| |
V V
Takes language | 21 | 17 |
-----------------
Doesn't take language | 12 | 4 |
It should be one hundred twenty six (126) if my math is correct