Triangle pqr is a right triangle. If PQ = 8, what is PR?

A guy wire is a cable used to restrain objects from moving. They are used to support towers or poles. A guy wire is attached to

Tanya [424]

Answer:

Step-by-step explanation:

8 0

3 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

-2x+5/-5x-7 simplify

Yakvenalex [24]

Hello from MrBillDoesMath!

Answer:

-3x - 7

Discussion:

The order of operations states that multiplication and division are done before addition\subtraction. So

-2x +5/-5x - 7 =

-2x + (5/-5x) - 7 -

-2x -x -7 =

-3x - 7

Thank you,

MrB

3 0

3 years ago

One lunch table can hold 10 students. There are 60 students in 3rd grade. How many lunch tables are needed so that every student

Sladkaya [172]

Answer:

6 lunch tables

Step-by-step explanation:

Since one lunch table can hold 10 students and 60 students are needed to hold,

60 ÷ 10 = 6 lunch tables

5 0

3 years ago

Read 2 more answers

Brooke has 24 pencils and 36 erasers. If she makes identical goodie bags for her friends with no pencils or erasers left over, w

Licemer1 [7]

I think the answer is 12 because the greatest common factor of 24 and 36 is 12.

Hope this helped☺☺

(That means each goody bag will have 2 pencils and 3 erasers)

8 0

3 years ago