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3 years ago

Please help me with this!! IMPORTANT!!

Mathematics

1 answer:

s344n2d4d5 [400]3 years ago

7 0

Answer:

Step-by-step explanation:

HELO

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(x-4) + 34 = -4x I need this answer

mote1985 [20]

The answer would be x= -6

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3 years ago

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Tpy6a [65]

Answer:

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Step-by-step explanation:

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2 years ago

From a sample with nequals8, the mean number of televisions per household is 4 with a standard deviation of 1 television. Using

OlgaM077 [116]

Answer:

75% of the households have between 2 and 6 televisions

Step-by-step explanation:

From the question, we can deduce the following;

sample size n= 8

sample mean μ = 4

standard deviation σ = 1

Using Chebychev’s theorem;

P(2 ≤ X ≤ 6) = P(2-4 ≤ (X - μ) ≤ 6-4)

= P(-2 ≤ (X-μ) ≤ 2) = P(|X-μ| ≤ kσ) ≥ (1 - 1/k^2) ≥ (1- 1/2^) = 1- 0.25 = 0.75 ( same as 75%)

3 0

3 years ago

Show that if X is a geometric random variable with parameter p, then

Lubov Fominskaja [6]

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:"

$P(X=x)=(1-p)^{x-1} p$

Let X the random variable that measures the number os trials until the first success, we know that X follows this distribution:

$X\sim Geo (1-p)$

In order to find the expected value E(1/X) we need to find this sum:

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

Lets consider the following series:

$\sum_{k=1}^{\infty} b^{k-1}$

And let's assume that this series is a power series with b a number between (0,1). If we apply integration of this series we have this:

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