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2 years ago

I really need help,please!!

Mathematics

1 answer:

Margaret [11]2 years ago

5 0

Answer
D
Explanation because I know

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What is the value of y in the solution to the following system of equations? 5x − 3y = −11 2x − 6y = −14 −1 0 1 2

Alekssandra [29.7K]

5x - 3y = -11 (×2)
2x - 6y = -14 (x5)

10x - 6y = -22
10x - 30y = -70
---------------------- -
24y = 48
y = 2

5 0

2 years ago

Determine whether a probability distribution is given. If a probability distribution is given, find its mean and standard deviat

drek231 [11]

Answer:

$E(X) = \sum_{i=1}^n X_i P(X_i) = 0*0.031 +1*0.156+ 2*0.313+3*0.313+ 4*0.156+ 5*0.031 = 2.5$

We can find the second moment given by:

$E(X^2) = \sum_{i=1}^n X^2_i P(X_i) = 0^2*0.031 +1^2*0.156+ 2^2*0.313+3^2*0.313+ 4^2*0.156+ 5^2*0.031 =7.496$

And we can calculate the variance with this formula:

$Var(X) =E(X^2) -[E(X)]^2 = 7.496 -(2.5)^2 = 1.246$

And the deviation is:

$Sd(X) = \sqrt{1.246}= 1.116$

Step-by-step explanation:

For this case we have the following probability distribution given:

X 0 1 2 3 4 5

P(X) 0.031 0.156 0.313 0.313 0.156 0.031

The expected value of a random variable X is the n-th moment about zero of a probability density function f(x) if X is continuous, or the weighted average for a discrete probability distribution, if X is discrete.

The variance of a random variable X represent the spread of the possible values of the variable. The variance of X is written as Var(X).

We can verify that:

$\sum_{i=1}^n P(X_i) = 1$

And $P(X_i) \geq 0, \forall x_i$

So then we have a probability distribution

We can calculate the expected value with the following formula:

$E(X) = \sum_{i=1}^n X_i P(X_i) = 0*0.031 +1*0.156+ 2*0.313+3*0.313+ 4*0.156+ 5*0.031 = 2.5$

We can find the second moment given by:

$E(X^2) = \sum_{i=1}^n X^2_i P(X_i) = 0^2*0.031 +1^2*0.156+ 2^2*0.313+3^2*0.313+ 4^2*0.156+ 5^2*0.031 =7.496$

And we can calculate the variance with this formula:

$Var(X) =E(X^2) -[E(X)]^2 = 7.496 -(2.5)^2 = 1.246$

And the deviation is:

$Sd(X) = \sqrt{1.246}= 1.116$

6 0

3 years ago

Please help me pleaseee

jekas [21]

Answer: A - sin 63

Step-by-step explanation:

3 0

2 years ago

Matthew's dad is 5 times as old as him. If the differences of their ages is 28, how old is matthew?

enyata [817]

Answer:

Step-by-step explanation:

5x-x=28 The dad is 5 times as old and the difference in their ages is 28years.

4x=28 Simplify and divide.

x=7

6 0

2 years ago

X + 3 - 3=-6 show all work

docker41 [41]

Answer:

x = -6

Step-by-step explanation:

$x+3-3=-6~(Given)\\x=-6~(Combine~like~terms)$

5 0

2 years ago