A class has 6 boys and 14 girls. What is the ratio in simplest form that compares number of boys to total number of students?

An individual who has automobile insurance from a certain company is randomly selected. Let Y be the number of mov- ing violatio

olga2289 [7]

Answer:

a) $E(Y) = \sum_{i=1}^n Y_i P(Y_i)$

And replacing we got:

$E(Y) =0*0.60 +1*0.25 +2*0.1 +3*0.05 = 0.60$

b) $E(Y^2) =0^2*0.60 +1^2*0.25 +2^2*0.1 +3^2*0.05 = 1.1$

And then the expected value would be:

$E(100Y^2) = 100*1.1= 110$

Step-by-step explanation:

We assume the following distribution given:

Y 0 1 2 3

P(Y) 0.60 0.25 0.10 0.05

Part a

We can find the expected value with this formula:

$E(Y) = \sum_{i=1}^n Y_i P(Y_i)$

And replacing we got:

$E(Y) =0*0.60 +1*0.25 +2*0.1 +3*0.05 = 0.60$

Part b

If we want to find the expected value of $100 Y^2$ we need to find the expected value of Y^2 and we have:

$E(Y^2) = \sum_{i=1}^n Y^2_i P(Y_i)$

And replacing we got:

$E(Y^2) =0^2*0.60 +1^2*0.25 +2^2*0.1 +3^2*0.05 = 1.1$

And then the expected value would be:

$E(100Y^2) = 100*1.1= 110$

4 0

3 years ago

If you help ill give you some of my banana milk...

snow_tiger [21]

Given:

The function is:

$f(x)=4x^2-25x-21$

To find:

The domain of the given function.

Solution:

Domain is the set of input values.

We have,

$f(x)=4x^2-25x-21$

It is a quadratic polynomial.

We know that a quadratic polynomial is defined for all real values of x. So, the given function is defined for all real values of x and the domain of the given function is:

Domain = Set of all real number

Domain = (-∞,∞)

Therefore, the correct option is B.

3 0

3 years ago

Hi if u could help me that would be great, have a nice day!!!

LenaWriter [7]

Hey there! I'm happy to help!

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OVERVIEW

Random sampling is when you take a sample of something completely at random. This is done to avoid bias and other stuff like that. It makes the data a lot more pure, real, and factual.

-------------------------------------------------------------------

CHOOSING THE ANSWER

OPTION A: A SCHOOL NEWSPAPER ASKS TEACHERS IN THAT MIDDLE SCHOOL HOW THEY FEEL ABOUT THE BEHAVIOR OF TWELVE YEAR OLD BOYS.

Does this seem very random to you? They're asking all the teachers who work at a certain junior high to talk about twelve year old boys. But, the teachers are definitely going to have some sort of bias towards twelve year old boys because they work with them, and since all of the samples are teachers, this is going to have biased data. Therefore, answer A is incorrect.

OPTION B: A NATIONAL SURVEY COMPANY PICKS ONE PHONE NUMBER FROM EACH AREA CODE IN AMERICA TO CALL AND ASK FOR AN OPINION ON CURRENT POLITICAL ISSUES.

This definitely seems a lot more random. There is only one phone number from each area code and there are many area codes in the United States so you get a bit of what everyone thinks about an issue. There is no bias because there is one random phone number and there are many different places this is done. Therefore, option B is correct.

OPTION C: MIGRANT WORKERS ARE SURVEYED ON THEIR OPINION OF MANDATORY HEALTH INSURANCE FOR COMPANIES.

This is not very random because they are asking a specific group of workers about a company and business ordeal. It is not very random because the migrant workers are specifically being asked, not random people. Therefore, option C is incorrect.

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THE SOLUTION

Therefore, Option B is the correct answer.

I hope that this helps! Have a wonderful day!

7 0

3 years ago

PLEASE HELP I REALLY NEED HELP ON THIS

jeka94

Answer:

One piece of fabric: 10 x 6, or 60.

If one triangle is 15, she can cut 4 triangles from each piece of fabric.

If she has 24 pieces of fabric, she can cut 4 x 24, or 96 triangle patches.

Let me know if this helps!

4 0

3 years ago

Solve the system using substitution. y - 3x = 1 2y - x = 12 ([?], [])

anyanavicka [17]

Answer:

(2, 5)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Equality Properties

Algebra I

Solving systems of equations using substitution/elimination

Step-by-step explanation:

Step 1: Define Systems

y - 3x = 1

2y - x = 12

Step 2: Rewrite Systems

y - 3x = 1

Add 3x on both sides: y = 3x + 1

Step 3: Redefine Systems

y = 3x + 1

2y - x = 12

Step 4: Solve for x

Substitution

Substitute in y: 2(3x + 1) - x = 12
Distribute 2: 6x + 2 - x = 12
Combine like terms: 5x + 2 = 12
Isolate x term: 5x = 10
Isolate x: x = 2

Step 5: Solve for y

Define equation: 2y - x = 12
Substitute in x: 2y - 2 = 12
Isolate y term: 2y = 10
Isolate y: y = 5

4 0

3 years ago