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harkovskaia [24]

2 years ago

11

Ginger has 12 plastic bead containers. The containers measure 1 inch on each side. How many rectangular prisms, each with a diff

erent-size base, could Ginger make by stacking all the bead containers

1 answer:

nignag [31]2 years ago

4 0

12 shjakakchvwbsmaouf didn’t be. Yeh s Wuxi m you don’t know what you mean

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In th xy plane, what is the y intercept of the graph of the equation y=2(x+3)(x-4)

vazorg [7]

The y-intercept is x-4.

3 0

3 years ago

Last year a baseball team paid $20 per bat and $12 per glove spending a total of $1040 this year the prices went up to $25 per b

Sonja [21]

<span>20x + 12y = 1040
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-12y' to each side of the equation. 20x + 12y + -12y = 1040 + -12y Combine like terms: 12y + -12y = 0 20x + 0 = 1040 + -12y 20x = 1040 + -12y Divide each side by '20'. x = 52 + -0.6y
thats the first part
then we have
</span>25x + 16y = 1350
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-16y' to each side of the equation.
25x + 16y + -16y = 1350 + -16y
Combine like terms:
16y + -16y = 0 25x + 0 = 1350 + -16y
25x = 1350 + -16y
Divide each side by '25'. x = 54 + -0.64y

7 0

2 years ago

Four buses carrying 146 high school students arrive to Montreal. The buses carry, respectively, 32, 44, 28, and 42 students. One

Naily [24]

Answer:

The expected value of X is $E(X)=\frac{2754}{73} \approx 37.73$ and the variance of X is $Var(X)=\frac{226192}{5329} \approx 42.45$

The expected value of Y is $E(Y)=\frac{73}{2} \approx 36.5$ and the variance of Y is $Var(Y)=\frac{179}{4} \approx 44.75$

Step-by-step explanation:

(a) Let X be a discrete random variable with set of possible values D and probability mass function p(x). The expected value, denoted by E(X) or $\mu_x$ , is

$E(X)=\sum_{x\in D} x\cdot p(x)$

The probability mass function $p_{X}(x)$ of X is given by

$p_{X}(28)=\frac{28}{146} \\\\p_{X}(32)=\frac{32}{146} \\\\p_{X}(42)=\frac{42}{146} \\\\p_{X}(44)=\frac{44}{146}$

Since the bus driver is equally likely to drive any of the 4 buses, the probability mass function $p_{Y}(x)$ of Y is given by

$p_{Y}(28)=p_{Y}(32)=p_{Y}(42)=p_{Y}(44)=\frac{1}{4}$

The expected value of X is

$E(X)=\sum_{x\in [28,32,42,44]} x\cdot p_{X}(x)$

$E(X)=28\cdot \frac{28}{146}+32\cdot \frac{32}{146} +42\cdot \frac{42}{146} +44 \cdot \frac{44}{146}\\\\E(X)=\frac{392}{73}+\frac{512}{73}+\frac{882}{73}+\frac{968}{73}\\\\E(X)=\frac{2754}{73} \approx 37.73$

The expected value of Y is

$E(Y)=\sum_{x\in [28,32,42,44]} x\cdot p_{Y}(x)$

$E(Y)=28\cdot \frac{1}{4}+32\cdot \frac{1}{4} +42\cdot \frac{1}{4} +44 \cdot \frac{1}{4}\\\\E(Y)=146\cdot \frac{1}{4}\\\\E(Y)=\frac{73}{2} \approx 36.5$

(b) Let X have probability mass function p(x) and expected value E(X). Then the variance of X, denoted by V(X), is

$V(X)=\sum_{x\in D} (x-\mu)^2\cdot p(x)=E(X^2)-[E(X)]^2$

The variance of X is

$E(X^2)=\sum_{x\in [28,32,42,44]} x^2\cdot p_{X}(x)$

$E(X^2)=28^2\cdot \frac{28}{146}+32^2\cdot \frac{32}{146} +42^2\cdot \frac{42}{146} +44^2 \cdot \frac{44}{146}\\\\E(X^2)=\frac{10976}{73}+\frac{16384}{73}+\frac{37044}{73}+\frac{42592}{73}\\\\E(X^2)=\frac{106996}{73}$

$Var(X)=E(X^2)-(E(X))^2\\\\Var(X)=\frac{106996}{73}-(\frac{2754}{73})^2\\\\Var(X)=\frac{106996}{73}-\frac{7584516}{5329}\\\\Var(X)=\frac{7810708}{5329}-\frac{7584516}{5329}\\\\Var(X)=\frac{226192}{5329} \approx 42.45$

The variance of Y is

$E(Y^2)=\sum_{x\in [28,32,42,44]} x^2\cdot p_{Y}(x)$

$E(Y^2)=28^2\cdot \frac{1}{4}+32^2\cdot \frac{1}{4} +42^2\cdot \frac{1}{4} +44^2 \cdot \frac{1}{4}\\\\E(Y^2)=196+256+441+484\\\\E(Y^2)=1377$

$Var(Y)=E(Y^2)-(E(Y))^2\\\\Var(Y)=1377-(\frac{73}{2})^2\\\\Var(Y)=1377-\frac{5329}{4}\\\\Var(Y)=\frac{179}{4} \approx 44.75$

8 0

3 years ago

You bought the new PS5 and 4 games for $660. the PS5 cost $499 and each game cost the same amount. Write an equation that can be

nirvana33 [79]

4x+499=660
X=40.25
X equeals the amount for each game.

4 0

2 years ago

What work do i need to show?

stealth61 [152]

You have to show finding the square root of it ______ ___ __
√144x^2 + √225 = √0
which will give you 12x+15=0
12x=15
x=5/4

4 0

2 years ago