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3 years ago

2x(x-1000)-x+1000=0 tìm x

Mathematics

1 answer:

TiliK225 [7]3 years ago

6 0

Answer:

x=0,5 và x=1000

Step-by-step explanation:

=>2x²-2000x-x+1000=0

=>(2x²-x)(-2000x+1000)=0

=>(2x-1)(x-1000)=0

=>[2x-1=0

=>[x-1000=0

=>x=1/2=0,5 và x=1000

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Can someone help me with this .

nekit [7.7K]

Answer:

D. 7

Step-by-step explanation:

to find the median the equation is to write out all the numbers given in order from least to greatest.

4, 4, 6, 6, 7, 7, 9, 9, 10

now cross off 1 number from each side. and keep doing thaf until you find the median, aka the middle number.

4, 6, 6, 7, 7, 9, 9

cross off the first and last number that remains.

6, 6, 7, 7, 9

again until 1 number remains **that number left will be the median**

6, 7, 7

cross off first and last.

7 will be the median.

I hope this helps!! if you need more explanation let me know and I will supply more information.

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morgandy

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2 years ago

Let X denote the distance (m) that an animal moves from its birth site to the first territorial vacancy it encounters. Suppose t

worty [1.4K]

Answer:

a) $P(X \leq 100) = 1- e^{-0.01342*100} =0.7387$

$P(X \leq 200) = 1- e^{-0.01342*200} =0.9317$

$P(100\leq X \leq 200) = [1- e^{-0.01342*200}]-[1- e^{-0.01342*100}] =0.1930$

b) $P(X>223.547) = 1-P(X\leq 223.547) = 1-[1- e^{-0.01342*223.547}]=0.0498$

c) $m = \frac{ln(0.5)}{-0.01342}=51.65$

d) $a = \frac{ln(0.05)}{-0.01342}=223.23$

Step-by-step explanation:

Previous concepts

The exponential distribution is "the probability distribution of the time between events in a Poisson process (a process in which events occur continuously and independently at a constant average rate). It is a particular case of the gamma distribution". The probability density function is given by:

$P(X=x)=\lambda e^{-\lambda x}$

Solution to the problem

For this case we have that X is represented by the following distribution:

$X\sim Exp (\lambda=0.01342)$

Is important to remember that th cumulative distribution for X is given by:

$F(X) =P(X \leq x) = 1-e^{-\lambda x}$

Part a

For this case we want this probability:

$P(X \leq 100)$

And using the cumulative distribution function we have this:

$P(X \leq 100) = 1- e^{-0.01342*100} =0.7387$

$P(X \leq 200) = 1- e^{-0.01342*200} =0.9317$

$P(100\leq X \leq 200) = [1- e^{-0.01342*200}]-[1- e^{-0.01342*100}] =0.1930$

Part b

Since we want the probability that the man exceeds the mean by more than 2 deviations

For this case the mean is given by:

$\mu = \frac{1}{\lambda}=\frac{1}{0.01342}= 74.516$

And by properties the deviation is the same value $\sigma = 74.516$

So then 2 deviations correspond to 2*74.516=149.03

And the want this probability:

$P(X > 74.516+149.03) = P(X>223.547)$

And we can find this probability using the complement rule:

$P(X>223.547) = 1-P(X\leq 223.547) = 1-[1- e^{-0.01342*223.547}]=0.0498$

Part c

For the median we need to find a value of m such that:

$P(X \leq m) = 0.5$

If we use the cumulative distribution function we got:

$1-e^{-0.01342 m} =0.5$

And if we solve for m we got this:

$0.5 = e^{-0.01342 m}$

If we apply natural log on both sides we got:

$ln(0.5) = -0.01342 m$

$m = \frac{ln(0.5)}{-0.01342}=51.65$

Part d

For this case we have this equation:

$P(X\leq a) = 0.95$

If we apply the cumulative distribution function we got:

$1-e^{-0.01342*a} =0.95$

If w solve for a we can do this:

$0.05= e^{-0.01342 a}$

Using natural log on btoh sides we got:

$ln(0.05) = -0.01342 a$

$a = \frac{ln(0.05)}{-0.01342}=223.23$

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3 years ago

The director of marketing at a large company wants to determine if the amount of money spent on internet marketing is a good pre

nevsk [136]

Answer: The value of the residual for advertising dollars spent equal to $1,020 and Profit equal to $17,500 is $417

Profit=372.6+17.2 (advertising dollars)
Advertising dollars=$1,020
Predicted Profit=372.6+17.2 (1,020)→
Predicted Profit=372.6+17,544→
Predicted Profit=$17,916.6

Residual=Predicted Profit-Profit→
Residual=$17,916.6-$17,500→
Residual=$416.6
Rounded to the nearest integer:
Residual=$417

Answer: The value of the residual for advertising dollars spent equal to $1,020 and Profit equal to $17,500 is $417

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4 years ago

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Plurality Method
Every person votes for his/her favorite candidate. The candidate receiving the most votes is declared the winner

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3 years ago

Calculate |4+7i| the absolute value of 4+7i is equal to the square root of ____

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Answer:

sqrt(65)