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.
You want to take 837 out of 36.
you can get 837 out of 3 0 times so you tack on the 6(0)
you get 837 out of 36 0 times so you tack on a zero(00)
Because you are adding a 0, you are now creating a decimal
you get 837 out of 360 0 times so you tack on a 0 (00.0)
You get 837 out of 3600 4 times so you put the 4 after the 0s (00.04)
Now you multiply 4 and 837 to get 3,348 and take that away from 3600 to get 252
Not you tack on a 0.
You get 837 out of 2520 3 times so you tack the 3 on behind the 4. (0.043)
Because of significant digits, your answer is 0.043
Answer:
Step-by-step explanation:
120.
To find out how much gas he is using per day, you can use 75/5 which comes to 15. Then multiplying 15 with the 8 days, you get a sum of 120.
9514 1404 393
Answer:
455
Step-by-step explanation:
The decrease was 30% of 650, or ...
0.30 · 650 = 195
So, the population this year is ...
650 -195 = 455
