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2 years ago

Which is the more reasonable measurement of the distance between the tracks on a railroad:

1 answer:

nataly862011 [7]2 years ago

6 0

If you're comparing 1.435 * 10^(-3) mm to 1.435 * 10^3 mm, then the more reasonable measurement is 1.435 * 10^3 mm since,

1.435 * 10^3 mm = 1435 mm = 1.435 meters

1 meter is about 3.28 feet approximately

So 1.435 meters is slightly larger (about 4.708 feet) which is a fairly reasonable distance between the tracks on a railroad.

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Something like 1.435 * 10^(-3) mm is equal to 0.001435 mm, which is far less than 1 mm.

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2 years ago

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nlexa [21]

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Step-by-step explanation:

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Answer:

$\sum_{k=1}^{\infty} \frac{p(1-p)^{k-1}}{k}=-\frac{p ln p}{1-p}$

Step-by-step explanation:

The geometric distribution represents "the number of failures before you get a success in a series of Bernoulli trials. This discrete probability distribution is represented by the probability density function:"

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Lets consider the following series:

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$\int_{0}^b \sum_{k=1}^{\infty} r^{k-1}=\sum_{k=1}^{\infty} \int_{0}^b r^{k-1} dt=\sum_{k=1}^{\infty} \frac{b^k}{k}$ (a)

On the last step we assume that $0\leq r\leq b$ and $\sum_{k=1}^{\infty} r^{k-1}=\frac{1}{1-r}$ , then the integral on the left part of equation (a) would be 1. And we have:

$\int_{0}^b \frac{1}{1-r}dr=-ln(1-b)$

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$\sum_{k=1}^{\infty} \frac{b^{k-1}}{k}=\frac{1}{b}\sum_{k=1}^{\infty}\frac{b^k}{k}=-\frac{ln(1-b)}{b}$

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$\sum_{k=1}^{\infty} \frac{p(1-p)^{k-1}}{k}=-\frac{p ln p}{1-p}$

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2 years ago

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2 years ago

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It would be easier to think it through if instead for 70 we took the number 100. Lets reword it and say what percent of 100 is 38? This would be easy to answer it would be 38% But how you check it is, you take 38 and divide by the total (100) which is .38 then multiply by 100 you will get 38% Same with your equation take the 10.5 and divide by the total amount which is 70 you will get .15 then multiply by 100. the answer will be 15%

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2 years ago

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