Answer:
D)
Explanation:
I honestly don't like this question. It's a really poor question. But anyway, here's the explanation:
1) All search results are <em>somewhat </em>relevant. They have the keyword "cell phone" in every result. So none should be considered off-topic.
2) Matching personal opinion with given answer choices.
My personal list if any, would have been 3, 1, 2, 4.
But since the author has helped as out, 3 and 2 are guaranteed to be the top choices, the last part is determining whether search result 4 is more relevant compared to 2.
Since I believe 1 is somewhat relevant, A and C are negated. Leaving, B and D. In this situation, I would prefer 1 than 4 since search result 4 doesn't exactly help your research paper compared to search result 1. Therefore, the only choice is D.
Ok happy to help any time
Finding the new mean is simple: If ![E[X]=10](https://tex.z-dn.net/?f=E%5BX%5D%3D10)
, then ![E[2X]=2E[X]=20](https://tex.z-dn.net/?f=E%5B2X%5D%3D2E%5BX%5D%3D20)
.
Meanwhile, the standard deviation is the square root of the variance, which is given by
![V[X]=E[X^2]-E[X]^2\implies V[2X]=E[(2X)^2]-E[2X]^2=4E[X^2]-(2E[X])^2](https://tex.z-dn.net/?f=V%5BX%5D%3DE%5BX%5E2%5D-E%5BX%5D%5E2%5Cimplies%20V%5B2X%5D%3DE%5B%282X%29%5E2%5D-E%5B2X%5D%5E2%3D4E%5BX%5E2%5D-%282E%5BX%5D%29%5E2)
![\implies V[2X]=4\underbrace{\left(E[X^2]-E[X]^2\right)}_{V[X]}=12](https://tex.z-dn.net/?f=%5Cimplies%20V%5B2X%5D%3D4%5Cunderbrace%7B%5Cleft%28E%5BX%5E2%5D-E%5BX%5D%5E2%5Cright%29%7D_%7BV%5BX%5D%7D%3D12)
and so the new standard deviation would be ![\sqrt{V[2X]}=\sqrt{12}=2\sqrt3](https://tex.z-dn.net/?f=%5Csqrt%7BV%5B2X%5D%7D%3D%5Csqrt%7B12%7D%3D2%5Csqrt3)
.
If the bill is stupid like stopping at railroad tracks even though it's not coming they might vote against it
