What causes an echo?
rarefaction
reflection
refraction

81 percentile of the given test is 482

The square root of the means of the squared deviations from the arithmetic mean is known as the standard deviation. Standard deviation is used in finance to quantify the risks associated with an investment instrument.

Given that the Marble Academy of Whoville conducts an annual test for all high school juniors one year, the scores on the test were approximately normally distributed with a mean of 420 and a standard deviation of 70

Here mean μ = 420 and Standard deviation σ = 70

We have find 81 percentile of this test = ?

The z score corresponding to the area 0.81 is

Z = 0.88  By standard normal table

X = μ + z σ

X = 420 + 0.88 x 70

= 420 + 62

= 482

Therefore 81 percentile of this test is 482

To learn more about standard deviation visit

https://brainly.com/question/16555520

#SPJ4

Yes, you are safe to land, If the landing angle at an airport is 4° and you are two miles out and ½ mile high.

The final approach, also known as the final leg or final approach leg, is the last leg of an aircraft's approach to landing in aviation. During this leg, the aircraft is aligned with the runway and descending for a landing. In aircraft radio lingo, it is frequently abbreviated to "final".

Given,

If the landing angle at an airport is 4° and you are two miles out and ½ mile high,

Yes, you are safe to land.

A normal airport landing pattern calls for aircraft to turn from the base leg to the final within 0.5 to 2 miles of the airport when visual meteorological conditions (VMC) are present. A "straight-in" final approach, when all other legs are skipped, is frequently employed for instrument approaches as well as VFR approaches onto controlled airfields. At American non-towered airports, straight-in approaches are discouraged.

To learn more about the angle, visit:

https://brainly.com/question/1478514

#SPJ1

The option that is a a linear equation is B. 4x - 2 = 20.

An equation is the statement that illustrates that the variables given. In this case, two or more components are taken into consideration to describe the scenario.

It is vital to note that an equation is a mathematical statement which is made up of two expressions that are connected by an equal sign

This is illustrated as 4x - 2 = 20

4x = 20 + 2

4x = 22

x = 22/4 = 5.5

This illustrates an equation.

Learn more about equations on:

brainly.com/question/2972832

#SPJ1

For the given four congruent parallelograms and the shaded area of 192cm² then value of x is equal to 8cm.

As given in the question,

Given four congruent parallelograms

Shaded area of the parallelogram is 192cm²

As four parallelograms are congruent

Let the area of each parallelogram is A

4A = 192

⇒A = 48cm²

For two parallelogram base length = 24cm

Base length of each parallelogram = 12cm

Area of parallelogram = base × height

48 = 12 × height

⇒ height = 4cm

Value of x = 2 times of height

                = 2 (4)

                = 8cm

Therefore, for the given four congruent parallelograms and the shaded area of 192cm² then value of x is equal to 8cm.

Learn more about area here

brainly.com/question/27683633

#SPJ1

The probability 11.1% of domestic airfares within the United States are $250 or less.

The formula for the z score is -

z = (x - μ)/σ

In which,

Substitute the value in formula.

P(x ≤ 250) = (250 - 385)/100

P(x ≤ 250) = -1.22

Select the p value from negative z score table;

P(x ≤ 250) = 0.111

P(x ≤ 250) = 11.1%

Thus, 11.1% of domestic flights within the United States are $250 or less.

To know more about the standard deviation, here

https://brainly.com/question/475676

#SPJ4

Answer:a. 24

b. 14

Step-by-step explanation:

a. 3ab=

3*a*b=

3*4*2=

12*2=24

b. a+5b=

a+5*b=

4+5*2=

4+10=14

Answer: a) 24

              b) 14

Step-by-step explanation:

step1: We have to substitute the numbers.

step2: Then finish the answer.

a) 3ab = 3 x 4 x 2 = 24

b) a+5b = 4 + 5 x 2 = 4 + 10 = 14

Answer:

Step-by-step explanation:

Isabella,  do you know how to do the "elementary row operations"?

Also, when did they begin teaching  linear algebra in H.S.  :DDD  nice work getting there.

Gauss Jordan, just mean get your matrix in RREF  (Reduced Row Echelon Form)

I suggest using Matlab to do this.  it's got the  "RREF(x)  function to do this exact thing.  

Your teacher probably wants you to do this by hand.  thou, huh.  :/  

here is my Matlab code and the answer

clc

close all

clear

format compact

A=[3 -4 2;0 -1 7]

mymatx=rref(A)

A =

    3    -4     2

    0    -1     7

mymatx =

   1.0000         0   -8.6667

        0    1.0000   -7.0000

Yes, maybe it's totally cheating, but it seems fair nowadays to use technology that is commonly available.    :)

So answer A) looks right

The equivalent ratios table is:

Toss     Dollars  

5             2

30           12

45           18

See the diagram in the attachment that shows the plotted points.

Equivalent ratios are ratios that have the same value when they are compared together.

For example, 4/6 = 2/3, therefore, the equivalent ratios are 2:3 and 4:6.

Create an equation that models equivalent ratios that can be used to complete the table if:

x = toss

y = dollars

Therefore, given that 30 toss equals $12,

Constant of proportionality, k = y/x = 12/30

k = 2/5.

Plug in the value of k into y = kx:

y = 2/5x.

Therefore:

2 dollars (y = 2), will give:

2 = 2/5(x)

x = 10/2

x = 5 toss

45 tosses (x = 45) will need:

y = 2/5(45)

y = 18 dollars

The equivalent ratios table would be:

Toss | Dollars  

5           2

30        12

45         18

The graph below shows the points, (5, 2), (30, 12), and (45, 18), where y = dollars, and x = toss.

Learn more about equivalent ratios on:

https://brainly.com/question/2914376

#SPJ1

Answer:

9 i think

Step-by-step explanation:

The number of centerpieces that she can make, using proportions, is of:

25.

A proportion is a fraction of an amount, and this fraction is combined with the unit rates in the context of a problem, and basic arithmetic operations, especially multiplication or division, to find the desired amounts in the same context of this problem.

In the context of this problem, the number of centerpieces is given by the division of the the total number of flowers by the number of flowers in each centerpiece.

The amounts are given as follows:

Hence the division giving the number of flowers per centerpiece is:

n = 430/17 = 25.2.

The amount is rounded down to 25, as for 26 centerpieces, more flowers would be needed.

Hailey is making floral centerpieces for a wedding. Each centerpiece has 17 flowers. She has 430 flowers for the project.

How many complete centerpieces can she make? Find the exact answer.

More can be learned about proportions at https://brainly.com/question/24372153

#SPJ1

A model for representing the relationship between the number of key chains and the number of feet of cotton cord is: 8x - 3y = 0.

Since Lucia creates braided key chains from out cotton cord and can create 3 braided key chains per each 8 feet of cotton cord she does have, the following equations must be performed via cross multiplication to symbolize the relationship between both the feet of cotton cord as well as the number of key chains but also obtain the number of cotton cord Lucia requires to achieve 5 key chains:

8 cotton cords = 3 key chains

Let the total length in feet of cotton cords be x.

And the total number of key chain made be y.

Then, the linear equation formed as;

8x = 3 y

8x - 3y = 0

Thus, a model for representing the relationship between the number of key chains and the number of feet of cotton cord is: 8x - 3y = 0.

To know more about the linear equation, here

https://brainly.com/question/2030026

#SPJ4

[tex]{ \green{ \sf{G = \sqrt{ ab}}}}[/tex]

[tex]{ \green{ \sf{G = \sqrt{ (ab³)(a³b)}}}}[/tex]

[tex]{ \green{ \sf{G = \sqrt{ a⁴b⁴}}}}[/tex]

[tex]{ \red{ \boxed{ \pink{ \sf{G = \sqrt{ a².b²}}}}}}[/tex]

T-test paired two samples for means should be used .

What does test score mean?

here the samples are dependent, the score of one twins is compared with the score of any another from the same pair .

Hence, T-test paired two samples for means should be used

Learn more about test score

brainly.com/question/13378052

#SPJ4

Answer:

15 minutes

Step-by-step explanation:

The 3/4 of an hour is,

→ 60 × (3/4)

→ 180/4 = 45

Now required time spend on rope is,

→ 45 × (1/3)

→ 45/3 = 15 minutes

Hence, he had spend 15 minutes.

1. The length of RS is 5.

2. The length of JK is 6.

3. The length of RT is 4.

4. The perimeter of triangle JKL is 24.

What do you mean by right angle triangle?

A right triangle, also known as a right-angled triangle, right-perpendicular triangle, orthogonal triangle, or formerly rectangled triangle, is a triangle with one right angle, or two perpendicular sides. The foundation of trigonometry is the relationship between the sides and various angles of the right triangle.

According to data in the diagram of the given question:

We have :

The ΔJKL, ΔRKS and ΔRTS are right-angle triangle.

The length of RK=3 and KS=4

We are using pythagoras theorem for determine the length of RS,

(RK)²+(KS)²=(RS)²

(3)²+(4)²=(RS)²

9+16=(RS)²

25=(RS)²

(5)²=(RS)²

RS=5

∴ The the length of RS is 5.

Now, we need to find the length of JK,

JK=2(RK)=2(3)=6

JK=6       [Because RK is midpoint of the side JK]

We have given value of KS=4 and the side KS is the opposite side of RT,

So, that's why the value of RT=4.

Now, we will find the perimeter of ΔJKL,

JK=6, KL=8 and we need to find the side JL,

(JK)²+(RL)²=(JL)²

(6)²+(8)²= (JL)²

36+64=(JL)²

100=(JL)²

(10)²=(JL)²

JL=10

The perimeter of the triangle ΔJKL,

Perimeter=6+8+10=24

Therefore, the perimeter of the triangle is 24.

To know more about right angle triangle visit:

https://brainly.com/question/3770177?referrer=searchResults

#SPJ1

Answer:

x + 3 = 18

Step-by-step explanation:

original number of kids: x

additional kids: 3

new total number of kids: x + 3

actual total number of kids: 18

Equation: x + 3 = 18

The function (g∘f)(x) expressed as a polynomial in standard form is  9x² - 36x + 40

A function can be defined as an equation, a rule or a law that shows or rather explain the relationship between two variables in an equation.

The variables are known as;

We have the function given;

To determine the composite function (g ∘f)(x), we have to substitute the value of x as fx) in the function g(x), we have;

(g∘f)(x) = (- 3x + 5)² + 2( -3x + 5) + 5

expand the bracket

(g∘f)(x) = 9x² - 15x - 15x + 25 - 6x + 10 + 5

Now, collect like terms, we get;

(g∘f)(x) = 9x² - 15x - 15x - 6x + 25 + 10 + 5

Add or subtract the like terms, we get;

(g∘f)(x) = 9x² - 36x + 40

The polynomial is written as;  9x² - 36x + 40

Hence, the value is  9x² - 36x + 40

Learn more about functions here:

https://brainly.com/question/25638609

#SPJ1

The circumference of the circle with a radius of 16.8 cm is 105.504 cm

The given parameters are

Radius = 16.8 cm

As a general rule, radius are represented by the variable r

So, we have the following representation equation

r = 16.8 cm

The circumference of the circle is then calculated as

C = 2πr

Next, we substitute the value of the variable r in the above equation

i.e. r = 16.8 cm

So, we have the following equation

C = 2π * 16.8 cm

From the question, we have

π = 3.14

So, we have the following equation

C = 2 * 3.14 *16.8 cm

Evaluate the products

So, we have the following equation

C = 6.28 *16.8 cm

Evaluate the products

C = 105.504 cm

Hence, the circumference is 105.504 cm

Read more about circumference at

brainly.com/question/12823137

#SPJ1

After solving the value of x in the equation is x [tex]=[/tex] -9  .

In the question ,

it is given that ,

the equation is 1/4(8x+12)  =  -15

Applying the associative property of multiplication ,

we get ,

8x/4 + 12/4 = -15

cancelling out the common factor 2 from numerator and denominator ,

we get ,

2x + 3 = -15

Subtracting the number 3 from both sides of the equation ,

we get ,

2x = -15 - 3

2x = -18

Dividing both sides of the equation above by the number 2 ,

we get ,

x = -18/2

x = -9

Therefore , After solving the value of x in the equation is x [tex]=[/tex] -9  .

The given question is incomplete , the complete question is

Solve the given equation for x ?

1/4(8x+12)= -15  

Learn more about Equations here

https://brainly.com/question/28735218

#SPJ1

Answer:

g(10) = -12

Step-by-step explanation:

Mean Value Theorem

If f is continuous on [a, b] and differentiable on (a, b), then there is a number c  such that a < c < b and:

[tex]f'(c)=\dfrac{f(b)-f(a)}{b-a}[/tex]

We are told that the function g(x) is continuous on the closed interval [8, 10] and differentiable on the open interval (8, 10).

Therefore:

Given:

As 8 < 8.5 < 10 then c = 8.5:

[tex]\begin{aligned} \implies g'(8.5)=\dfrac{g(10)-g(8)}{10-8}&=-9\\\\\dfrac{g(10)-6}{2}&=-9\\\\g(10)-6&=-18\\\\g(10)&=-12\end{aligned}[/tex]

The range of the function is [0, 960]

From the question, we have the equation of the function to be

f(x) = 16x

Where

When the dispenser is empty, it means that f(x) = 0

When the dispenser is full, it means that f(x) = 960

When these values are combined, they represent the range

In other words, the range is 0 to 960

This can be rewritten as [0, 960]

Read more about range at

https://brainly.com/question/2264373

#SPJ1

Answer:

big black men

Step-by-step explanation:

(i have your search history)

The probability to win two or more tickets in the lottery is 0.118

It is given that there is a 5% chance to win a lottery ticket.

Therefore, the probability to win a lottery ticket is

0.05

The girl here plays the game 12 times. The above distribution is clearly a Binomial Distribution

ⁿCₓ  X  pˣ  X  (1 - p)ⁿ⁻ˣ

We need to calculate the probability to win 2 or more tickets

= 1 - the probability to win at least one ticket

= 1 - P(X = 0) + P(X = 1)

here,

p = 0.05

1 - p = 0.95

n = 12

P(X = 0)

= ¹²C₀  X  0.05⁰  X  0.95¹²

= 0.54036

P(X = 1)

= ¹²C₁  X  0.05¹  X  0.95¹¹

= 0.34128

Hence we get

P(X ≥ 2) = 1 - 0.54036 - 0.34128

= 0.118

Therefore, we get the probability that the person will win 2 or more tickets to be 0.118

To learn more about Probability visit

https://brainly.com/question/14210034

#SPJ4

Answer:

8.50x + 6.00y < 60 and y > 3.

Please consider the complete question.

Amy's restaurant has a budget of at most $60 to spend this month on gourmet coffee. All international blends cost $8.50 per package and all house blends cost $6.00 per package. She would like to purchase some global combinations and at least 3 boxes of the house blends. Write a system of linear inequalities that describes this situation.

Let x represent the number of international blends and y represent the number of house blends.

The cost of x international blends would be and the cost of y house blends would be.

Since Amy's restaurant has a budget of at most $60 to spend this month on gourmet coffee, so the cost of x international blends and y house blends should be less than or equal to 60.

We can represent this information in an inequality as:

Since Amelia wants to purchase at least 3 packages of the house blends, so y should be greater than or equal to 3. We can represent this information in an inequality as:

Therefore, our required system of inequalities would be 8.50x + 6.00y < 60 and y > 3.

Step-by-step explanation:

After applying the distributive property, Ezra's expression was 8y + 16.

After he used the commutative property, his expression was 16 + 8y.

When using the distributive property, we are able to expand an expression with a bracket by multiplying the things in the bracket with the things outside:

8( y + 2)  becomes:

= (8 x y) + (8 x 2)

= 8y + 16

The commutative property on the other hand, means that when adding, the position of the number does not matter. For instance, a + b = b + a

When the commutative property is applied therefore, we get:
8y + 16 = 16 + 8y

Find out more on the commutative property at https://brainly.com/question/778086

#SPJ1

Answer:

8 feet

Step-by-step explanation:

there's 12 inches in 1 foot so 12 x 8 = 96

Answer:

f(5) = -5

Step-by-step explanation:

To find the value of f(5), find the value of y when x = 5.

To find the value of y from a given value of x, find the position of x on the x-axis, then trace vertically until you meet the line.

Once you meet the line, trace horizontally to the y-axis to find the corresponding value of y.

Therefore, the value of f(5) is -5.

See attachment.

Answer:

Step-by-step explanation:

Given the graph of the function f(x).

In order to find the value of f for any value of x on the graph, find the point x on the x-axis, then add a vertical line from this point to the graph. The y-coordinate of the intersection is the value of the function at given x-coordinate.

We are asked to find the value of f(5).

This is f(5) = - 5 as per above explanation.

See the attached for better understanding.

The true statement about the sentence 'sample of gas is enclosed in a container of fixed volume' are:

When a sample of gas is been enclosed in a container of fixed volume then then if the container temperature is been reduced then the kinetic energy of the gas will reduce.

Therefore the first and the third option are correct.

Read more about gas at:

https://brainly.com/question/25736513

#SPJ1

Nine (9) cards must be selected from the standard 52 deck to guarantee that at least three cards are chosen from the same suit.

What is the pigeon-hole approach?
According to the pigeonhole principle, at least one container must hold more than one item if n things are placed into m containers, where n > m. For instance, if one possesses three gloves but none of them are ambidextrous or reversible, then there must be at least two right-handed gloves or at least two left-handed gloves since there are three items but only two categories of handedness. It is possible to establish potentially surprising consequences using this seemingly obvious assertion, a type of counting argument.

The standard 52 deck has 4 suits of 13 cards each, thus as per n pigeons need to be extracted from p = 4 pigeon-holes; as per established literature above.
∴ [(n - 1) / p] + 1 = 3 ⇒ [(n - 1) / 4] + 1 = 3 ⇒ n - 1 = 8 ⇒ n = 8 + 1 ⇒ n = 9
Therefore, nine (9) cards must be selected from the standard 52 deck to guarantee that at least three cards are chosen from the same suit.

To learn more about this, tap on the link below:
https://brainly.com/question/10559888

#SPJ4