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2 years ago

10

The ratio of the number of boys to the number of girls at a school is 4:5. If there are 120 boys, how many students are there al

together?

1 answer:

frutty [35]2 years ago

8 0

Answer: 270 students altogether

There are 150 girls.

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Identify the undefined term that best models each object. a crease in a garment.

zvonat [6]

Answer:#carry on learning

Mark me as brainliest

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The three undefined terms are point, line, and plane. Thus, figure D represents an undefined term as it's a line.

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3 years ago

A car dealership sells 0, 1, or 2 luxury cars on any day. When selling a car, the dealer also tries to persuade the customer to

melisa1 [442]

Answer:

Mean = 1.42

Variance = 0.58

Step-by-step explanation:

Given: X denote the number of luxury cars sold in a given day, and Y denote the number of extended warranties sold.

Also, joint probability function of X and Y are given.

To find:

mean and variance of X

Solution:

From the given joint probability function of X and Y,

$P(X=0)=\frac{1}{6}\\P(X=1)=\frac{1}{12}+\frac{1}{6}=\frac{1+2}{12}=\frac{3}{12}\\P(X=2)=\frac{1}{12}+\frac{1}{3}+\frac{1}{6}=\frac{1+4+2}{12}=\frac{7}{12}$

Mean of X:

$E(X)=\sum XP(X)\\=0\left ( \frac{1}{6} \right )+1\left ( \frac{3}{12} \right )+2\left ( \frac{7}{12} \right )\\=0+\frac{3}{12}+\frac{14}{12}\\=\frac{17}{12}=1.42$

Variance of X:

$E(X^2)=\sum X^2P(X)\\=0^2\left ( \frac{1}{6} \right )+1^2\left ( \frac{3}{12} \right )+2^2\left ( \frac{7}{12} \right )\\=0+\frac{3}{12}+\frac{28}{12}\\=\frac{31}{12}$

$var(X)=E\left [ X^2 \right ]-\left ( E\left [ X \right ] \right )^2\\=\frac{31}{12}-\left ( \frac{17}{12} \right )^2\\=\frac{31}{12}-\frac{289}{144}\\=\frac{372-289}{144}\\=\frac{83}{144}\\=0.58$

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3 years ago

An object is 3.6 m from the pinhole. Its image is 4.2 cm from the opposite side of the pinhole. The height of the image is 0.8 c

madreJ [45]

Answer:

Height of the object is 68.6 cm.

Step-by-step explanation:

The height of the object can be determined by:

$\frac{object distance from pinhole}{image distance from pinhole}$ = $\frac{object height}{image height}$

From the given question;

object distance from pinhole = 3.6 m = 360 cm

image distance from pinhole = 4.2 cm

height of image = 0.8 cm

So that;

$\frac{360}{4.2}$ = $\frac{object height}{0.8}$

⇒ object height = $\frac{360*0.8}{4.2}$

= $\frac{288}{4.2}$

= 68.571

object height = 68.6 cm

Thus, the height of the object is 68.6 cm.

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3 years ago

PLEASE HELP! Which of the following is a discrete random variable? a) length of time you play in a baseball game b) length of a

wlad13 [49]

Answer:

The answer is D: the number of candies in a box.

Step-by-step explanation:

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3 years ago

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$1,200, 3.9%, 8months

LUCKY_DIMON [66]

The answer is 1-28/2992/8 ow

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3 years ago