WNAE, an all-news AM station, finds that the distribution of the lengths of time listeners are tuned to the station follows the normal distribution. The mean of the distribution is 15.0 minutes and the standard deviation is 3.5 minutes. What is the probability that a particular listener will tune in:

Complete question:

Para ingresar a la Universidad del Chocó se aplica una prueba de razonamiento que consta de 30 preguntas. Por cada respuesta correcta se asignan 5 puntos y por cada incorrecta (o no contestada) se restan 2 puntos. Si un participante obtuvo un puntaje de 94 puntos, ¿cuantas preguntas respondió bien?

Responder:

número de respuestas correctas = 22

Explicación paso a paso:

Dado lo siguiente:

Número total de preguntas = 30

Deje respuestas correctas = y; Respuestas incorrectas = n

Marca otorgada por y = 5

Marca deducida por n = 2

Si el total de preguntas = 30; luego

y + n = 30 - - - - (1)

Puntuación total obtenida = 94; luego

5y - 2n = 94 - - - (2)

De 1),

y + n = 30

y = 30 - n

Sustituya y = 30 - n en equ (2)

5 (30 - n) - 2n = 94

150 - 5n - 2n = 94

150 - 7n = 94

-7n = 94-150

-7n = - 56

n = 56/7

n = 8

Sustituir n = 8 en (1)

y + n = 30

y + 8 = 30

y = 30 - 8

y = 22

y = número de respuestas correctas = 22

n = número de respuestas incorrectas = 8

Usando un sistema de ecuaciones, se encuentra que el participante obtuve 22 respuestas correctas.

En el sistema, x es el número de respuestas correctas, con y siendo el número de respuestas incorrectas.

Total de 30 preguntas, o sea:

[tex]x + y = 30 \rightarrow y = 30 - x[/tex]

5 puntos asignados por cada respuesta correcta, 2 restados por cada respuesta incorrecta. Puntaje de 94 puntos, o sea:

[tex]5x - 2y = 94[/tex]

Considerando [tex]y = 30 - x[/tex]

[tex]5x - 60 + 2x = 94[/tex]

[tex]7x = 154[/tex]

[tex]x = \frac{154}{7}[/tex]

[tex]x = 22[/tex]

El participante obtuve 22 respuestas correctas.

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Answer:

Your ans is. a12 = 47/12

Step-by-step explanation:

First, you need to find if the series has a common ratio or a common difference between each term. Based from observation, there is a common difference of 1/3 so the series is an arithmetic series.

The solution for this problem goes like this

an=a1+(n-1)d

a12=1/n+(12-1)(1/3)

a12=47/12

Hope it helped you.. Please mark BRAINLIEST

Tysm

Answer:

Step-by-step explanation:

First, for end behavior, the highest power of x is x^3 and it is positive. So towards infinity, the graph will be positive, and towards negative infinity the graph will be negative (because this is a cubic graph)

To find the zeros, you set the equation equal to 0 and solve for x

x^3+2x^2-8x=0

x(x^2+2x-8)=0

x(x+4)(x-2)=0

x=0   x=-4   x=2

So the zeros are at 0, -4, and 2. Therefore, you can plot the points (0,0), (-4,0) and (2,0)

And we can plug values into the original that are between each of the zeros to see which intervals are positive or negative.

Plugging in a -5 gets us -35

-1 gets us 9

1 gets us -5

3 gets us 21

So now you know end behavior, zeroes, and signs of intervals

Hope this helps

The zeroes of the function are -4, 0 and 2.

The intervals where the function is positive is [tex]-4 < x < 2, \ \ x >2[/tex].

The intervals where the function is negative is [tex]x < -4[/tex].

The given parameters:

The zeroes of a function is the possible values of the unknown that makes the entire function to be zero.

The zeroes of the cubic equation is calculated as follows;

f(x) = 0

x³ + 2x² - 8x

factorize as follows;

[tex]x(x^2 + 2x -8) = 0\\\\x(x^2 + 4x - 2x -8) = 0\\\\x[x (x + 4 )-2(x + 4)]= 0\\\\x(x + 4)(x -2)=0\\\\x = 0, \ \ x = -4 \ \ x = 2[/tex]

The intervals where the function is positive and negative is determined as follows;

[tex]x(x + 4) (x - 2)\\\\[/tex]

[tex]when, \ x = -5, \ f(x) = -ve\\\\when, \ x = -4, \ f(x) =0\\\\when , \ x = -3, \ f(x) = +ve[/tex]

The intervals where the function is positive is determined as;

[tex]-4 < x < 2, \ \ x >2[/tex]

The intervals where the function is negative is determined as;

[tex]x < -4[/tex]

Learn more about graph of cubic equation here: https://brainly.com/question/8878887

Answer:

a. See Attachment 1

b. [tex]PT = 12.3\ m[/tex]

c. [tex]HT = 31.1\ m[/tex]

d. [tex]OH = 28.4\ m[/tex]

Step-by-step explanation:

Calculating PT

To calculate PT, we need to get distance OT and OP

Calculating OT;

We have to consider angle 50, distance OH and distance OT

The relationship between these parameters is;

[tex]tan50 = \frac{OT}{20}[/tex]

Multiply both sides by 20

[tex]20 * tan50 = \frac{OT}{20} * 20[/tex]

[tex]20 * tan50 = OT[/tex]

[tex]20 * 1.1918 = OT[/tex]

[tex]23.836 = OT[/tex]

[tex]OT = 23.836[/tex]

Calculating OP;

We have to consider angle 30, distance OH and distance OP

The relationship between these parameters is;

[tex]tan30 = \frac{OP}{20}[/tex]

Multiply both sides by 20

[tex]20 * tan30 = \frac{OP}{20} * 20[/tex]

[tex]20 * tan30 = OP[/tex]

[tex]20 * 0.5774= OP[/tex]

[tex]11.548 = OP[/tex]

[tex]OP = 11.548[/tex]

[tex]PT = OT - OP[/tex]

[tex]PT = 23.836 - 11.548[/tex]

[tex]PT = 12.288[/tex]

[tex]PT = 12.3\ m[/tex] (Approximated)

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

Calculating the distance between H and the top of the tower

This is represented by HT

HT can be calculated using Pythagoras theorem

[tex]HT^2 = OT^2 + OH^2[/tex]

Substitute 20 for OH and [tex]OT = 23.836[/tex]

[tex]HT^2 = 20^2 + 23.836^2[/tex]

[tex]HT^2 = 400 + 568.154896[/tex]

[tex]HT^2 = 968.154896[/tex]

Take Square Root of both sides

[tex]HT = \sqrt{968.154896}[/tex]

[tex]HT = 31.1\ m[/tex] (Approximated)

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

Calculating the position of H

This is represented by OH

See Attachment 2

We have to consider angle 50, distance OH and distance OT

The relationship between these parameters is;

[tex]tan50 = \frac{OH}{OT}[/tex]

Multiply both sides by OT

[tex]OT * tan50 = \frac{OH}{OT} * OT[/tex]

[tex]OT * tan50 = {OH[/tex]

[tex]OT * 1.1918 = OH[/tex]

Substitute [tex]OT = 23.836[/tex]

[tex]23.836 * 1.1918 = OH[/tex]

[tex]28.4= OH[/tex]

[tex]OH = 28.4\ m[/tex] (Approximated)

Answer:

Option (B)

Step-by-step explanation:

There are two lines on the graph representing the system of equations.

First line passes through two points (-3, 1) and (-2, 3).

Slope of the line = [tex]\frac{y_2-y_1}{x_2-x_1}[/tex]

                           = [tex]\frac{3-1}{-2+3}[/tex]

                       m = 2

Equation of the line passing through (x', y') and slope = m is,

y - y' = m(x - x')

Equation of the line passing through (-3, 1) and slope = 2 will be,

y - 1 = 2(x + 3)

y = 2x + 7 ----------(1)

Second line passes through (0, 1) and (-1, 4) and y-intercept 'b' of the line is 1.

Let the equation of this line is,

y = mx + b

Slope 'm' = [tex]\frac{y_2-y_1}{x_2-x_1}[/tex]

               = [tex]\frac{4-1}{-1-0}[/tex]

               = -3

Here 'b' = 1

Therefore, equation of the line will be,

y = -3x + 1 ---------(2)

From equation (1) and (2),

2x + 7 = -3x + 1

5x = -6

x = [tex]-\frac{6}{5}[/tex]

x = [tex]-1\frac{1}{5}[/tex]

From equation (1),

y = 2x + 7

y = [tex]-\frac{12}{5}+7[/tex]

  = [tex]\frac{-12+35}{5}[/tex]

  = [tex]\frac{23}{5}[/tex]

  = [tex]4\frac{3}{5}[/tex]

Therefore, exact solution of the system of equations is [tex](-1\frac{1}{5},4\frac{3}{5})[/tex].

Option (B) will be the answer.

Answer:

B. (-1 1/5, 4 3/5)

Step-by-step explanation:

Answer:

A) [tex]1<x<\infty[/tex]

Step-by-step explanation:

Given:

A graph of a function.

When we analyze the given graph, it is of a parabola.

To find:

The interval of values of [tex]x[/tex] where the function is increasing.

Solution:

First of all, let us learn about the meaning of increasing and decreasing functions.

1. A function [tex]y=f(x)[/tex] is known as increasing  in an interval [tex]a<x<b[/tex] when

Value of y keeps on increasing when we move from the value of x from a to b.

2. A function [tex]y=f(x)[/tex] is known as decreasing  in an interval [tex]a<x<b[/tex] when

Value of y keeps on decreasing when we move from the value of x from a to b.

On analyzing the given graph , we can see that the graph is decreasing on the interval: [tex]-\infty<x<1[/tex]

and is increasing on the interval: [tex]1<x<\infty[/tex]

When we choose from the options,

The correct answer is option A) [tex]1<x<\infty[/tex]

Answer:

Her annual salary is approximately $41,667

Step-by-step explanation:

Hello,

This question deals with percentage of a number and it's very easy :)

First of all, get the data and understand what's required of us.

Pam spends $7500 yearly on expenses

But this amount represents 18% of her annual income.

Let her annual income be represented by x

18% = 7500 / x

18÷100 = 7500÷x

cross multiply and solve for x

18 × x = 7500 × 100

18x = 750,000

divide both sides by 18

18x / 18 = 750,000 / 18

x = $41,666.67

x = $41,667

Her annual salary is approximately $41,667

Answer:

7.5kilometer

Step-by-step explanation:

for 30mins semin runs 5kilometer

then for 1min: (1min×5kilometer)÷30mins,

therefore, for 45mins: (45mins×5kilometer)÷30mins=7.5kilometer

From the given information:

We are being informed that Samin can run for 5 kilometers in 30 minutes;

If Samin can run such a kilometer in 30 minutes;

5 kilometers = 30 minutes

∴

In x kilometers = 45 minutes

By cross multiplying;

(x × 30 minutes) = 5 kilometers × 45 minutes

30x = 225 kilometer/minutes

[tex]x = \dfrac{225 \ kilometer/minutes}{30 minutes}[/tex]

[tex]\mathbf{x = 7.5 \ kilometers}[/tex]

Therefore, we can conclude that the Samin can run 7.5 kilometers in 45 minutes.

Learn more about word problems here:

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Answer:

p < 2

Step-by-step explanation:

9p + 23 < 41

p < 2

Answer:

p < 2

Step-by-step explanation:

9p + 23 < 41

9p < 18

p < 2

w is the width and it is the independent variable. You can pick any positive whole number you want (within reason of course; you can't go to infinity or go beyond some set boundary). Whatever you picked for w, the expression 2w-5 will be dependent on it. So the length is dependent on the width.

For instance, if the width is w = 10 feet, then 2w-5 = 2*10-5 = 20-5 = 15 feet is the length. The choice of 10 feet for the width directly affects the length being 15 feet.

Answer:

Check the answer below.

Step-by-step explanation:

This is a very trivial but professional question. Note that all of millimetre, centimetre and metres are acceptable metric units but the millimetre is more preferable by builders and architects because:

1. It is easier to work with integer values on building and architectural plans, an advantage given by measuring and recording in millimetre.

2. working in millimetre allows for precision. The builder will record values that are very close to the true value

3. The measurement will be easily readable by anybody that sees it.

Answer:

Step-by-step explanation:

f(x) = 3x - 1

g(x) = 2x + 1

To find (f +g)(3) , first find (f + g)(x)

To find (f + g)(x) add g(x) to f(x)

That's

(f + g)(x) = 3x - 1 + 2x + 1

= 3x + 2x + 1 - 1

(f + g)(x) = 5x

Now to find (f + g)(3) substitute 3 into

(f + g)(x)

That's

(f +g)(3) = 5(3)

Hope this helps you

Answer:

27.8%

Step-by-step explanation:

P(male | Spanish) = P(male and Spanish) / P(Spanish)

P(male | Spanish) = 0.05 / 0.18

P(male | Spanish) = 0.278

The probability of the student being a male is 27.8%

Probability is defined as the ratio of the number of favorable outcomes to the total number of outcomes in other words the probability is the number that shows the happening of the event.

Probability = Number of favorable outcomes / Number of sample

Given that in a certain group of students, the probability of a randomly-chosen student being male is 40%, the probability of the student studying Spanish is 18%, and the probability of the student being a male who studies Spanish is 5%.

The probability of the student being a male will be calculated as below:-

P(male | Spanish) = P(male and Spanish) / P(Spanish)

P(male | Spanish) = 0.05 / 0.18

P(male | Spanish) = 0.278

Therefore, the probability of the student being a male is 27.8%

To know more about probability follow

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#SPJ5

Answer: The store must sell 40 bikes.

Step-by-step explanation:

y=60x+2400

y=120x

120x=60x+2400

-60x on both sides

60x=2400

divide 60 on both sides

2400/60=40

x=40  

Answer:

150

Step-by-step explanation:

Answer:

150  =  half of 300

± 180

230

soooo 230 students

Step-by-step explanation:

Answer:

18 meters

Step-by-step explanation:

If the width is w, the length is w + 7.

Perimeter = 2(width + length), therefore:

86 = 2(w + w + 7)

86 = 2(2w + 7)

43 = 2w + 7

36 = 2w

w = 18

Answer:

Step-by-step explanation:

Given,

Let length of a rectangle be ' x + 7 ' meters

Let width of a rectangle be ' x ' meters

Perimeter = 86 meters

Now, let's find the width of the rectangle:

Perimeter of rectangle = [tex]2(l + b)[/tex]

plug the values

[tex]86 = 2(x + 7 + x)[/tex]

Collect like terms

[tex]86 = 2(2x + 7)[/tex]

Distribute 2 through the parentheses

[tex]86 = 4x + 14[/tex]

Move constant to R.H.S and change its sign

[tex]86 - 14 = 4x[/tex]

Calculate the difference

[tex]72 = 4x[/tex]

Swipe the sides of the equation

[tex]4x = 72[/tex]

Divide both sides of the equation by 4

[tex] \frac{4x}{4} = \frac{72}{4} [/tex]

Calculate

[tex]x = 18[/tex] meters

Hope this helps..

Best regards!!

Answer:

p = 1

Step-by-step explanation:

Given that the system intersect at (4, q) then this point satisfies both equations, that is

q = 4² - 4(4) + 3

q = [tex]\frac{1}{2}[/tex] (4) + p

Equating both gives

16 - 16 + 3 = 2 + p, that is

3 = 2 + p ( subtract 2 from both sides )

p = 1

Answer:

72° and 45°

Step-by-step explanation:

The sum of the exterior angles of a polygon = 360°

Since the given polygons are regular, then

Pentagon (5 sides ) has

exterior angle = 360° ÷ 5 = 72°

Octagon ( 8 sides ) has

exterior angle = 360° ÷ 8 = 45°

Step-by-step explanation:

The exterior angle of a polygon is given by

360/n

where n is the number of sides

First figure

For the first shape it has five sides

That's it's a pentagon

The measure of one exterior angle of the shape is

360 / 5

= 72°

Second figure

For the second shape it has 8 sides that's it's an octagon

So the measure of one exterior angle of the shape is

360 / 8

= 45°

Hope this helps you

Answer:

[tex]\dfrac{10}{4} \ hour[/tex]

Step-by-step explanation:

Given that :

Jack had 4 hours of school.

He spent 45 minutes in the library

1/2 hour on a science lecture  and;

had a lunch break of 25 minutes

The objective is to determine how much time is left for the school to get over and we are to write the answer as a fraction.

In order to do that, we will have to convert the minutes into hours,

we all know that; 60 minutes = 1 hour.

Then,

45 minutes = (45/60)hour = 3/4 hour

25/60 minutes = 1/4 hour

Therefore, the amount of time left  for the school to get over is:

= [tex]4 - (\dfrac{3}{4}+\dfrac{1}{2}+ \dfrac{1}{4})[/tex]

=  [tex]\dfrac{16-(3+2+1)}{4}[/tex]

= [tex]\dfrac{16-6}{4}[/tex]

= [tex]\dfrac{10}{4} \ hour[/tex]

Answer:

first one

Step-by-step explanation:

Answer:

D: As the x-values go to negative infinity, the function's values go to positive infinity.

Step-by-step explanation:

Since we are dealing with end behavior, we look at the graph infinitely:

When x-values go to negative infinity, we see that f(x) values go to positive infinity.

When x-values go to positive infinity, we see that f(x) values also go to positive infinity.

Therefore. our only correct answer is D.

Answer:

x² + 4x + y² + 10y + 20 = 0

Step-by-step explanation:

Step 1: Expand (x + 2)²

x² + 2x + 2x + 4 + (y + 5)² = 9

Step 2: Combine like terms

x² + 4x + 4 + (y + 5)² = 9

Step 3: Expand (y + 5)²

x² + 4x + 4 + y² + 5y + 5y + 25 = 9

Step 4: Combine like terms

x² + 4x + 4 + y² + 10y + 25 = 9

Step 5: Move 9 over

x² + 4x + 4 + y² + 10y + 25 - 9 = 0

Step 6: Combine like terms

x² + 4x + y² + 10y + 20 = 0

Answer:

x^2+y^2+4x+10y+20=0

Step-by-step explanation:

(x+2)^2+(y+5)^2=9

x^2+4x+4+y^2+10y+25-9=0

general form: x^2+y^2+4x+10y+20=0

Answer:

23

Step-by-step explanation:

Raise 3 to the power of 3

27 - 4

Subtract 4 from 27

23

Hope this was correct

Answer:

23

Explanation:

step 1 - rewrite the expression with the value of x

[tex]x^3 - 4[/tex]

[tex](3)^3 - 4[/tex]

step 2 - solve the exponent

[tex](3)^3 - 4[/tex]

[tex]27 - 4[/tex]

step 3 - subtract

[tex]27 - 4[/tex]

[tex]23[/tex]

therefore, the value of the expression is 23.

Answer:

8685 butterflies

Step-by-step explanation:

Given the logistics growth function expressed as ​f(t)equals440 Over 1 plus 13.7 e Superscript negative 0.28 t which describes the population of a species of butterflies t months after they are introduced to a​ non threatening habitat, to know the number of butterflies expected butterflies are expected in the habitat after 20 ​months, we will substitute t = 20 into the function.

f(20) = 440/1+13.7exp-(0.28×20)

f(20) = 440/1+13.7exp-(5.60)

f(20) = 440/1+(13.7× 0.003698)

f(20) = 440/1+0.05066

f(20) = 440/1.05066

f(20) = 8684.9

This means there will be approximately 8685 butterflies in the habitat after 20months.

Answer:

[tex]p=- \frac{15}{2}[/tex]

[tex]p=2[/tex]

Step-by-step explanation:

[tex]2p^2+11p=30[/tex]

Subtract 30 on both sides.

[tex]2p^2+11p-30=30-30[/tex]

[tex]2p^2+11p-30=0[/tex]

Factor left side of the equation.

[tex](2p + 15)(p-2)=0[/tex]

Set factors equal to 0.

[tex]2p+15=0[/tex]

[tex]2p=-15[/tex]

[tex]p=\frac{-15}{2}[/tex]

[tex]p-2=0[/tex]

[tex]p=2[/tex]

Answer: it is =4176000000000000

Step-by-step explanation:

(2.9)(100000)(7.2)(10^2)

5(10^−8)

=

(290000)(7.2)(10^2)

5(10^−8)

=

2088000(10^2)

5(10^−8)

=

(2088000)(100)

5(10^−8)

=

208800000

5(10^−8)

=

208800000

5(1/100000000)=

208800000/1

20000000

=4176000000000000

hope i helped

-lvr

Answer: 42w

Step-by-step explanation:

Subtracting a negative is like adding.

Answer:

[tex] \boxed{\sf (a + 3)(a + 1)} [/tex]

Step-by-step explanation:

[tex] \sf Factor \: the \: following: \\ \sf \implies {a}^{2} + 4a + 3 \\ \\ \sf The \: factors \: of \: 3 \: that \: sum \: to \: 4 \\ \sf are \: 3 \: and \: 1. \\ \\ \sf So, \\ \sf \implies {a}^{2} + (3 + 1)a + 3 \\ \\ \sf \implies {a}^{2} + 3a + a + 3 \\ \\ \sf \implies a(a + 3) + 1(a + 3) \\ \\ \sf \implies (a + 3)(a + 1) [/tex]

Answer:

2√3

Step-by-step explanation:

Since this is a 30-60-90 triangle, we can find s by finding the short leg (bottom), then the hypotenuse (s).

To find the short leg, we can divide the long leg (which is 3mm) by sqrt 3 (also  √3, as any of them are fine), and we will have 3/√3. Since we don't want the square root on the bottom, we can multiply √3 on both sides, giving us 3√3/3, which is technically √3 because of simplifying.

Since you have the short leg now, you can find s. By finding s, you can multiply the short leg by 2, which will be √3 * 2 which is 2√3.

Answer:

answer is D

Step-by-step explanation:

f(x) = -2(-5) + 7

f(x) = 10 + 7 = 17

the solution is 17