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3 years ago

Can someone help me with this problem please

Mathematics

2 answers:

olchik [2.2K]3 years ago

7 0

Answer:

The answer is C.84 inches

Step-by-step explanation:

it is 84 inches because as you can see 3 times 7 is 21

5 times 7 is 35,6 times 7 is 42 and 8 times 7 is 56

so it makes sense,12 times 7 is 84

grigory [225]3 years ago

4 0

Answer:

the answer is C.84 inches

Step-by-step explanation:

it is 84 inches because as you can see 3 times 7 is 21

5 times 7 is 35,6 times 7 is 42 and 8 times 7 is 56

so it makes sense,12 times 7 is 84

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Ten pictures, each measuring 4 inches by 6 inches, are mounted on a piece of green poster board so that there is no overlap. The

alexandr1967 [171]

Answer:

100 square inches

Step-by-step explanation:

Dimension of each of the ten pictures= 4 inches by 6 inches

Area of one of the pictures=4*6=24 Square Inch.

Total Area of the 10 pictures=24*10=240 Square Inches.

Dimension of the Poster Board=20 inches by 17 inches.

Area of the Poster Board=20*17=340 Square Inches.

Area not covered by the pictures=340-240=100 Square Inches

Therefore, 100 square inches of the green background will show after the pictures are mounted.

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3 years ago

An art teacher mixes 20 ounces of yellow paint with 8 ounces of red paint. How many ounces of yellow paint would she need to mix

vlada-n [284]

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3 years ago

There are 6 girls and 7 boys in a class. A team of 10 players is to be selected from the class. How many different combinations

Anna71 [15]

13C10 = 13C3 = 13x12x11/(1x2x3) =
"286 ways".

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3 years ago

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(True or false)car traveling 20 meters per hour east of the mountain pass is example of velocity

stiv31 [10]

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3 years ago

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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