Answer: E(X) = 30; Var[X] = 180
Step-by-step explanation: This is a <u>Bernoulli</u> <u>Experiment</u>, i.e., the experiment is repeated a fixed number of times, the trials are independents, the only two outcomes are "success" or "failure" and the probability of success remains the same, So, to calculate <em><u>Expected</u></em> <em><u>Value</u></em>, which is the mean, in these conditions:

r is number of times it is repeated
p is probability it happens
Solving:

E(X) = 30
<u>Variance</u> is given by:
![Var[X]=\frac{r(1-p)}{p^{2}}](https://tex.z-dn.net/?f=Var%5BX%5D%3D%5Cfrac%7Br%281-p%29%7D%7Bp%5E%7B2%7D%7D)
![Var[X]=\frac{5(1-1/6)}{(1/6)^{2}}](https://tex.z-dn.net/?f=Var%5BX%5D%3D%5Cfrac%7B5%281-1%2F6%29%7D%7B%281%2F6%29%5E%7B2%7D%7D)
![Var[X]=5.\frac{5}{6}.6^{2}](https://tex.z-dn.net/?f=Var%5BX%5D%3D5.%5Cfrac%7B5%7D%7B6%7D.6%5E%7B2%7D)
Var[X] = 180
Expected Value and Variance of the number of times one must throw a die until 1 happens 5 times are 30 and 180, respectively.
Answer: X= 11
Step-by-step explanation:
9514 1404 393
Answer:
- red division: 6 teams
- blue division: 5 teams
Step-by-step explanation:
We can let r and b represent the numbers of teams in the red and blue divisions, respectively. The total number of goals scored in each division will be the average for that division times the number of teams in that division.
r - b = 1 . . . . . . there is 1 more red team than blue
4.5r +4.2b = 48 . . . . . . total goals scored per week
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Solving by substitution, we have ...
r = b +1
4.5(b +1) +4.2b = 48 . . . . substitute for r
8.7b +4.5 = 48 . . . . . . . . simplify
8.7b = 43.5 . . . . . . . . . . subtract 4.5
b = 43.5/8.7 = 5 . . . . . divide by 8.7
r = b +1 = 6 . . . . . . . . . find r
There are 6 red teams and 5 blue teams.
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<em>Additional comment</em>
The basic idea is that you make an equation for each relation given in the problem statement. For a problem like this, you do need to have an understanding of how the average number of goals would be calculated and how that relates to the total goals.
Answer:
-2
Step-by-step explanation:
Answer:
They give you the answer just keep going until you get the same answer or use the inverse of what they did
Step-by-step explanation: