What is the value of the expression (−2 4/5)÷(−1.4)

Answer:

C- are moving close together very quickly and then very far apart suddenly

Answer:

30 foot by 20 foot

Step-by-step explanation:

1 inch = 10 inch

2 foot = d foot

Cross products: 1xd=2x10

d=20foot

1 inch = 15 inch

2 foot = d foot

Cross products: 1xd=2x15

d=30foot

Answer:

The minimum sample size required to create the specified confidence interval is of 565.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.8}{2} = 0.1[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.1 = 0.9[/tex], so Z = 1.28.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

Found the standard deviation to be 1.3.

This means that [tex]\sigma = 1.3[/tex]

Error of no more than 0.07. What is the minimum sample size required to create the specified confidence interval?

This is n for which M = 0.07. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]0.07 = 1.28\frac{1.3}{\sqrt{n}}[/tex]

[tex]0.07\sqrt{n} = 1.28*1.3[/tex]

[tex]\sqrt{n} = \frac{1.28*1.3}{0.07}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.28*1.3}{0.07})^2[/tex]

[tex]n = 565.1[/tex]

Rounding up:

The minimum sample size required to create the specified confidence interval is of 565.

Answer:

x + y + z = 180 (this is the first equation)

w + z = 180 (this is the second equation)

Now, rewrite the second equation as z = 180 - w and substitute that for z in the first equation:

x + y + (180 - w) = 180

x + y - w = 0

x + y = w

Step-by-step explanation:

Answer:

See explanation:

Step-by-step explanation:

1: 180-50=130

3: vertical angles are the same, therefore 50

4: 180-50=130

5: angle 1 equals angle 5, therefore 130

6: 50

7: 50, angles 6 and 7 are vertical therefore equal

8: 180-50=130

Answer:

21

Step-by-step explanation:

21 and 27

You are only given an option of 21, so take it.

Answer:

its 21

Step-by-step explanation:

Answer:

D is the answer

Step-by-step explanation:

You just distribute the negative three and combine like terms

Answer:

High blood pressure

Step-by-step explanation:

Possible DEATH

Answer:

High blood pressure

Step-by-step explanation:

High blood pressure is dangerous

Step-by-step explanation:

know the normal large sample condition is not met and also there are outliers

Answer:

C

Step-by-step explanation:

No, the Normal/large sample condition is not met.

Answer:

use the app photomath its free. and shows you all the steps

Step-by-step explanation:

Answer:

a) The area to the left of 18 is 0.5.

b) The area to the left of 14 is if 0.309.

c) The area to the right of 17 is of 0.55.

d) The area to the right of 19 is of 0.45.

e) The area between 14 and 30 is of 0.624.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X, which is the area to the left of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X, which is the area to the right of X.

A variable is normally distributed with mean 18 and standard deviation 8

This means that [tex]\mu = 18, \sigma = 8[/tex]

a) Find the area to the left of 18.

This is the pvalue of Z when X = 18.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{18 - 18}{8}[/tex]

[tex]Z = 0[/tex]

[tex]Z = 0[/tex] has a pvalue of 0.5.

So the area to the left of 18 is 0.5.

b) Find the area to the left of 14.

This is the pvalue of Z when X = 14. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{14 - 18}{8}[/tex]

[tex]Z = -0.5[/tex]

[tex]Z = -0.5[/tex] has a pvalue of 0.309

The area to the left of 14 is if 0.309.

c) Find the area to the right of 17.

This is 1 subtracted by the pvaleu of Z when X = 17. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{17 - 18}{8}[/tex]

[tex]Z = -0.125[/tex]

[tex]Z = -0.125[/tex] has a pvalue of 0.45

1 - 0.45 = 0.55

The area to the right of 17 is of 0.55.

d) Find the area to the right of 19.

This is 1 subtracted by the pvaleu of Z when X = 19. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{19 - 18}{8}[/tex]

[tex]Z = 0.125[/tex]

[tex]Z = 0.125[/tex] has a pvalue of 0.55

1 - 0.55 = 0.45

The area to the right of 19 is of 0.45.

e) Find the area between 14 and 30.

This is the pvalue of Z when X = 30 subtracted by the pvalue of Z when X = 14.

X = 30

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{30 - 18}{8}[/tex]

[tex]Z = 1.5[/tex]

[tex]Z = 1.5[/tex] has a pvalue of 0.933

From b), when X = 14, Z has a pvalue of 0.309.

0.933 - 0.309 = 0.624

The area between 14 and 30 is of 0.624.

The area to the left of 18 is 0.5, the area to the left of 14 is 0.309, the area to the right of 17 is 0.55, the area to the right of 19 is 0.45, and the area between 14 and 30 is 0.624.

Given :

A variable is normally distributed with a mean of 18 and a standard deviation of 8.

a) Use the z score formula in order to determine the area to the left of 18.

[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]

[tex]\rm Z = \dfrac{18-18}{8}=0[/tex]

For the z = 0 the p-value is 0.5.

Therefore, 0.5 is the area to the left of 18.

b) Use the z score formula in order to determine the area to the left of 14.

[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]

[tex]\rm Z = \dfrac{14-18}{8}=-0.5[/tex]

For the z = -0.5 the p-value is 0.309.

Therefore, 0.309 is the area to the left of 14.

c) Use the z score formula in order to determine the area to the right of 17.

[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]

[tex]\rm Z = \dfrac{17-18}{8}=-0.125[/tex]

For the z = -0.125 the p-value is 0.45.

Therefore, the area to the left of 17 is given by:

= 1 - 0.45 = 0.55

d) Use the z score formula in order to determine the area to the right of 19.

[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]

[tex]\rm Z = \dfrac{19-18}{8}=0.125[/tex]

For the z = 0.125 the p-value is 0.55.

Therefore, the area to the left of 19 is given by:

= 1 - 0.55 = 0.45

e) Use the z score formula in order to determine the area between 14 and 30.

At X = 30 the z score becomes:

[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]

[tex]\rm Z = \dfrac{30-18}{8}=1.5[/tex]

For the z = 1.5 the p-value is 0.933.

For the z = -0.5 the p-value is 0.309.

Therefore, the area to the left of 14 is given by:

= 0.933 - 0.309

= 0.624

For more information, refer to the link given below:

https://brainly.com/question/13299273

Answer:

5(6-t)

Step-by-step explanation:

in math, product means the "sum" of the equation or the final answer

and in your case, that means 5*6, but then we also have to remember that we're "reducing" or subtracting 't'-

5(6-t)

good luck :)

i hope this helps

brainliest would be highly appreciated

have a nice day!

Sample space َََ َ َ َ َ َ َ َ َ َ

Answer:

8.25

Step-by-step explanation:

(8x 8) + (2x2) = x ^2

64 + 4 = x2

x = √68

x = 8.25

Answer:

Test statistic  |Z| = 0.1040 < 1.96 at 0.05 level of significance

Step-by-step explanation:

Step(i):-

Given that a report on the nightly news broadcast stated that 10 out of 108 households with pet dogs  were burglarized

First proportion

              [tex]p_{1} = \frac{x_{1} }{n_{1} } = \frac{10}{108} = 0.0925[/tex]

Given that a report on the nightly news broadcast stated that  20 out of 208 households without pet dogs were burglarized

Second proportion

              [tex]p_{2} = \frac{x_{2} }{n_{2} } = \frac{20}{208} = 0.0961[/tex]

where

           [tex]P = \frac{n_{1}p_{1} +n_{2}p_{2} }{n_{1} +n_{2} }[/tex]

         P = 0.09486

       Q = 1 - P = 1 - 0.09486 = 0.90514

Step(ii):-

Test statistic

        [tex]Z = \frac{p_{1}-p_{2} }{\sqrt{PQ(\frac{1}{n_{1} } +\frac{1}{n_{2} } )} }[/tex]

      [tex]Z = \frac{0.0925-0.0961 }{\sqrt{0.09486 X 0.90514(\frac{1}{108 } +\frac{1}{208 } )} }[/tex]

     Z =    -0.1040

|Z| = |-0.1040|

|Z| = 0.1040

Critical value Z = 1.96 at 0.05 level of significance

Step-by-step explanation:

x+ 2(7-x) = 11

x+14-2x = 11

-x = -3

x = 3

3+ y = 7

y = 4

x + 2(22-x) = 48

x + 44 -2x = 48

-x = 4

x = -4

-4 + y = 22

y = 26

y = 45-x

x + 2(45-x) = 36

x + 90 -2x = 36

-x = 54

x = -54

-54 + y = 45

y = 99

Answer:

1. x=3 and y=4

2. x=−4 and y=26

3. x=54 and y=−9

Step-by-step explanation:

1. x+y=7;x+2y=11

Step: Solvex+y=7for x:

x+y+−y=7+−y(Add -y to both sides)

x=−y+7

Step: Substitute −y+7 for x in x+2y=11:

x+2y=11

−y+7+2y=11

y+7=11(Simplify both sides of the equation)

y+7+−7=11+−7(Add -7 to both sides)

y=4

Step: Substitute 4 for y in x=−y+7:

x=−y+7  

x=−4+7

x=3(Simplify both sides of the equation)

2. x+y=22;x+2y=48

Step: Solve x+y=22 for x:

x+y+−y=22+−y(Add -y to both sides)

x=−y+22

Step: Substitute−y+22 for x in x+2y=48:

x+2y=48

−y+22+2y=48

y+22=48(Simplify both sides of the equation)

y+22+−22=48+−22(Add -22 to both sides)

y=26

Step: Substitute26 for y in x=−y+22:

x=−y+22

x=−26+22

x=−4(Simplify both sides of the equation)

3. x+y=45;x+2y=36

Step: Solve x+y=45 for x:

x+y+−y=45+−y(Add -y to both sides)

x=−y+45

Step: Substitute−y+45 for x in x+2y=36:

x+2y=36

−y+45+2y=36

y+45=36(Simplify both sides of the equation)

y+45+−45=36+−45(Add -45 to both sides)

y=−9

Step: Substitute−9 for y in x=−y+45:

x=−y+45

x=−(−9)+45

x=54(Simplify both sides of the equation)

I hope this helped!

Answer:

[tex]0.64 \pm 1.645\sqrt{\frac{0.64*0.36}{50}}[/tex], option D

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

From a random sample of 50 students, she found that 32 students read at least 1 book last month.

This means that [tex]n = 50, \pi = \frac{32}{50} = 0.64[/tex]

90% confidence level

So [tex]\alpha = 0.1[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].

Confidence interval:

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.64 \pm 1.645\sqrt{\frac{0.64*0.36}{50}}[/tex]

So the correct answer is given by option D.

Answer/Step-by-step explanation:

The triangle given is a right triangle

Reference angle = angle E

Thus:

The side that is opposite to angle E is side DF = e

The side that is adjacent to angle E is side EF = d

The hypotenuse side is the longest side that is opposite go the right angle of the triangle = DE = f

Answer:

Step-by-step explanation:

If we let the points in the first graph define the position and slope of a line through the points, this line would have a negative slope and a negative trend line.  As x increases, y decreases.

Answer: it’s A. I took the test.

Step-by-step explanation:

the Beatles are better than the stones and that is a fact

Answer:

18

Step-by-step explanation:

Let the number be 'x'

Sum of 'x' and 12 = x +12

The product of 8 and the sum of a number and 12 = 8* (x +12)

            = 8*x + 8*12

            = 8x + 96

8x + 96 = 240

Subtract 96 from both sides

8x  + 9 6 - 96  = 240 - 96

8x = 144

Divide both sides by 8

x = 144/8

x = 18

Answer:

Maybe B?

Step-by-step explanation:

Answer:

Ejercicios Resueltos  

ANGULOS  

1. Si el complemento de ángulo x es 2x, ¿Cuál es el valor de x en  

grados?  

Solución:  

2x x 90 += °

3x 90

x 90 / 3

x 30

= °

= °

= °

2. Si el suplemento del ángulo x es 5x, ¿Cuál es el valor de x?  

Solución:  

5x+x=180

6x=180

x=180 /6

x=30

°

°

°

°

3- Determínese los dos ángulos x e y, cuya suma es 90 y cuya  

diferencia es 10 .  

°

°

Solución:  

-Planteamos el sistema de ecuaciones:  

x y 90

x y 10

+= °

−= °

-Resolvemos el sistema. Mediante el método de suma y resta  

obtenemos:  

2x 100

x 100 / 2

x 50

= °

= °

= °

-Hacemos la sustitución del valor encontrado de x en la primera  

ecuación: 50 y 90

y 90 50

y 40

°+ = °

= °−

= °

°

∴La solución al problema es x 50 , y 40 =°= °

°

4. Hállense dos ángulos complementarios tales que su diferencia sea  

30° .  

Solución:  

-Planteamos el sistema de ecuaciones:  

x y 90

x y 30

+= °

−= °

-Resolvemos el sistema. Mediante el método de suma y resta  

obtenemos:  

2x 120

x 120 / 2

x 60

= °

= °

= °

-Hacemos la sustitución del valor encontrado de x en la primera  

ecuación:  

60 y 90

y 90 60

y 30

°+ = °

= °−

= °

∴La solución al problema es x 60 , y 30 = °= °

°

5. Hállense dos ángulos suplementarios tales que el uno sea 20 mayor  

que el otro.  

°

Solución:  

-Planteamos el sistema de ecuaciones:  

x y 180

x y 20

+= °

=+ °

-Resolvemos el sistema:  

(y 20 ) y 180

2y 180 20

2y 160

y 80

+ °+ =

= °− °

= °

= °

-Hacemos la sustitución del valor encontrado de y en la primera  

ecuación: x 80 180

x 180 80

x 100

+ °=

= °−

= °

°

°

∴La solución al problema es:  

x = °= ° 100 , y 180

TRIANGULOS  

1.- ¿Cuánto miden cada uno de los ángulos interiores del siguiente  

triángulo?  

Solución:  

Nota: La suma de los ángulos interiores de los triángulos es  

180° .  

((( A B C 180 ++= °

3x 5x 4x 180 ++ = °

12x 180 = °∴( ( (( A 22.5 , B 52.5 , C 30 , CBR 127.5 = ° = ° =° = °

x 15 = °

∴( ( A 45 , B 75 ,C 60 =° =°= °

°

°

°

°

°

°

2.- ¿Cuánto miden cada uno de los ángulos del siguiente triángulo?  

Solución  

a) Ángulo extendido  

( ( B CBR 180 + = Esto debido a que son ángulos suplementarios  

(B 15x 60 180 + − °=

(B 180 60 15x = °+ °−

(B 240 15x = °−

b) Suma de los ángulos interiores del triángulo  

((( A B C 180 ++=

3x (240 15x) 4x 180 + °− + =

7x (240 15x) 180 + °− =

− + °= 8x 240 180− =− 8x 160°

x 7.5 =

∴( ( (( A 22.5 , B 52.5 , C 30 , CBR 127.5 = ° = ° =° = °  

3.- Escribe la definición de bisectriz del triángulo.  

Es la semirrecta que biseca el ángulo, es decir, divide el ángulo  

en dos ángulos congruentes.  

4.- ¿Qué es la mediatriz de un triángulo?  

La mediatriz de un lado de un triángulo (y en general de un  

segmento de recta), es la recta perpendicular a ese lado en su  

punto medio.  

5.- ¿Que es la mediana de un triángulo?  

La mediana de un triángulo, es el segmento de la recta que une  

un vértice con el punto medio del lado opuesto.  

CUADRILATEROS  

1.- ¿Qué cuadrilátero tiene las dos diagonales iguales y sus lados son  

iguales dos a dos?  

Rectángulo  

2.- Si los ángulos de un cuadrilátero miden, respectivamente, 80º, 110º  

y 70º, ¿Cuánto medirá el ángulo que falta?  

100º

3.- ¿Cuál es el paralelogramo que tiene las diagonales perpendiculares?  

Rombo  

4.- ¿Cómo se llama el cuadrilátero que tiene dos lados paralelos?  

Trapecio  

5.- Encuentra el área del paralelogramo que tiene 5cm de base y 3 de  

altura  

A b*a

A 5*3

A 15

=

=

=

POLÍGONOS 1.- Cuatro ángulos interiores de un pentágono valen respectivamente  

110°, 90°, 85° y 125°. ¿Cuánto vale el quinto ángulo?  

Solución:  

Si la suma de los ángulos interiores de un polígono es:  

180°*(n-2)=180°*(5-2) = 540°, a lo que le se le resta los  

valores de los ángulos que se dieron, consecuentemente, el  

quinto ángulo vale 130°.  

2.- ¿Cuántos lados tiene, en cada caso, el polígono cuyos ángulos  

interiores suman respectivamente 1080°, 900°, 1260°?  

Solución:  

Despejando de la fórmula el valor de n, tenemos que:  

. 2

180

suma angulos n = ° + , y esto aplicado a cada valor de la suma de los  

ángulos internos, obtenemos que los valores de n son 8, 7 y 9  

respectivamente.  

3.- ¿Cuánto vale cada ángulo exterior de un octágono regular?  

Solución:  

Aplicando el teorema de que la suma de los ángulos exteriores  

de un polígono es 360°, entonces cada ángulo exterior vale  

360°/8 = 45°  

4.- Calcular los ángulos exteriores de un triángulo rectángulo que tiene  

un ángulo agudo doble del otro.  

Solución:  

Se tiene que la suma de los ángulos interiores es  

180°*(n-2)= 180° y éste a su vez es igual a 90° + x + 2x,  

despejando x de 3x = 90°, x= 30°, entonces los ángulos  

interiores son 30°, 60° y 90°, teniendo como ángulos exteriores  

150°, 120° y 90°.

Step-by-step explanation:

Answer:

The lowest possible IQ scores of students remaining in the class is 84.46.

The highest possible IQ scores of students remaining in the class is 115.54.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Mean of 100 and a standard deviation of 15.

This means that [tex]\mu = 100, \sigma = 15[/tex]

Find the lowest and highest possible IQ scores of students remaining in the class.

Lowest:

The 15th percentile, which is X when Z has a pvalue of 0.15, so X when Z = -1.036.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.036 = \frac{X - 100}{15}[/tex]

[tex]X - 100 = -1.036*15[/tex]

[tex]X = 84.46[/tex]

Highest:

The 100 - 15 = 85th percentile, which is X when Z has a pvalue of 0.85, so X when Z = 1.036.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.036 = \frac{X - 100}{15}[/tex]

[tex]X - 100 = 1.036*15[/tex]

[tex]X = 115.54[/tex]

The lowest possible IQ scores of students remaining in the class is 84.46.

The highest possible IQ scores of students remaining in the class is 115.54.

Answer:

$2,800

Step-by-step explanation:

The formula for simple interest is I = PRT, where I is the interest (earned or paid), P is the principal amount invested/borrowed, R is the rate in decimal form, and T is the time in years.

I = (2000)(0.05)(8)

I = $800

Then we add that to the principal to get $2,800

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

Joey made a deposit into an account that earns 6% simple interest. After 3 years, Joey earned $400. How much was Joey's initial deposit?

I = PRT

400 = P(0.06)(3)

400 = 0.18P

P = $2,222. 22

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

Peter is calculating the interest earned on a deposit of $275 in an account that earns 8% simple interest after 12 years. What is the ??? guessing interest earned?

I = PRT

I = (275)(0.08)(12)

I = $264

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

Neil's grandmother has left him a small inheritance of $6,000. Neil would like to invest it at a rate of 5% interest. What is the simple???

I = PRT

I = (6000)(0.05)(T)

Please let me know if you have questions, or want to fill in the missing information on questions 3 & 4.