Find the mean, variance, and standard deviation of the following probability

Mathematics

1 answer:

ElenaW [278]3 years ago

3 0

Answer:

5.1 ; 8.29 ; 2.879

Step-by-step explanation:

Given :

Number of Computer Sold X

Probability P(x)

0.1

0.2

0.3

0.2

Mean = E(X) = Σ(x*p(x)

E(X) = (0*0.1) + (2*0.2) + (5*0.3) + (7*0.2) + (9*0.2)

E(X) = 5.1

Variance, Var(X) = Σx²p(x) − E(X)²

Var(X) = [(0^2*0.1) + (2^2*0.2) + (5^2*0.3) + (7^2*0.2) + (9^2*0.2)] - 5.1^2

Var(X) = 34.3 - 26.01 = 8.29

Standard deviation ; Std(X) = √Var(X) = √8.29 = 2.879

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You are buying balloons for a party. A small balloon costs $2. A large balloon costs $4. Write an algebraic expression for the

miv72 [106K]

Answer:

2x + 4y

$40

Step-by-step explanation:

Equation for x small balloons and y large balloons

2x + 4y

Total cost of 10 small balloons and 5 large balloons

x = 10, y = 5

2(10) + 4(5)

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3 years ago

X + y = 15 5x - y = 9 Elimination method (4, ? ) what number is the ?

vovangra [49]

The ? Is 11.

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3 years ago

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Mike can plow a field in 12 hours and his brother Phil can plow it in 15 hours. How long will it take them to plow it if they us

Korvikt [17]

Answer:

6.66 hours, that is, 6 hours and 40 minutes.

Step-by-step explanation:

If Mike can plow a field in 12 hours, we plows 1/12 of the field each hour.

If Phil can plow a field in 15 hours, we plows 1/15 of the field each hour.

So if they are working together, they can plow (1/12) + (1/15) of the field each hour, that is:

(1/12) + (1/15) = (5 + 4) / 60 = 9 / 60 = 3 / 20 = 1 / 6.66