Question 1 of 12, Step 1 of 1
0/17
Correct
Two planes, which are 2800 miles apart, fly toward each other. Their speeds differ by 50 mph. If they pass each other in 4 hours, what is the sspeed of each?
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Answer:

Place value of 1 = 1 × 10 = 10

Step-by-step explanation:

In 382619,

Place of 1 = Tens

Place value of 1 = 1 × 10 = 10

Answer:

Evaluación de expresiones y polinomios

Purplemath

"Evaluación" significa principalmente "simplificar una expresión a un solo valor numérico". A veces se le dará una expresión numérica, donde todo lo que tiene que hacer es simplificar; esa es más una cuestión de orden de operaciones. En esta lección, me concentraré en el aspecto de la evaluación de "conectar y tragar": introducir valores para las variables y "avanzar" hasta llegar a la respuesta simplificada.

(Por cierto, sí, "plug-n-chug" es una terminología bastante estándar. No es un término "técnico", por lo que probablemente no lo verá en su libro de texto, pero seguramente lo escuchará de otros estudiantes. , y quizás también su instructor.)

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Evaluar expresiones

Por lo general, la única parte difícil de la evaluación es hacer un seguimiento de los signos "menos". Le recomiendo encarecidamente que utilice los paréntesis libremente, especialmente cuando recién está comenzando.

Evalúe a2b para a = –2, b = 3, c = –4 y d = 4.

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Para encontrar mi respuesta, simplemente conecto los valores dados, teniendo cuidado de usar paréntesis, particularmente alrededor de los signos "menos". Especialmente cuando recién estoy comenzando, dibujar los paréntesis primero puede ser útil:

a2 b

() 2 ()

(–2) 2 (3)

(4) (3)

12

Observe cómo el uso de paréntesis me ayudó a realizar un seguimiento del signo "menos" en el valor de a. Esto era importante, porque de otro modo podría haber elevado al cuadrado solo el 2, terminando con –4, lo que habría estado mal.

Por cierto, resultó que no necesitábamos los valores de las variables c y d. Cuando se le da un gran conjunto de expresiones para evaluar, debe esperar que a menudo haya una u otra de las variables que no se incluirán en ningún ejercicio en particular del conjunto.

Evalúe a - cd para a = –2, b = 3, c = –4 y d = 4.

En este ejercicio, me dieron información adicional. No hay una b en la expresión que quieren que evalúe, por lo que puedo ignorar este valor en mi trabajo:

(–2) - (–4) (4)

–2 - (–16)

–2 + 16

16 - 2

14

Step-by-step explanation:

hola

Answer:

Step-by-step explanation:

This appears to be an SSA application of solving the triangle

We have 2 sides, so we will use the law of cosines

The law of cosines defines for a triangle ABC with side a/b/c with corresponding angles A/B/C

a^2 = b^2+c^2 - 2*b*c * (cos A)

this applies to the other 2 sides

first using the pythagorean theorem we find that BC = sqrt(55)

then we substitute all 3 sides into our equation to find angle A

55 = 64 + 9 - 2*8*3* (cos A)

18 = 2*8*3(cos A)

3/8 = (cos A)

and angle A is approximately 68 degrees

Please check if I'm correct

Answer:

67.98°

Step-by-step explanation:

Given 2 sides, you can find the missing angle of a right triangle using basic trig functions.

Since Cos∅=adjacent/ hypotenuse, we can use the adjacent side to the angle, 3 and they hypotenuse, 8 in the ratio by doing 3/8. This is 0.375. Then we use the inverse cosine function to find the angle. This gives 67.98°

Or

Cos∅=0.375

Cos^-1= 67.98

Answer:

[tex]z = 1.6[/tex]

Step-by-step explanation:

Given

[tex]Pr = 0.05[/tex]

Required

The z value to the right

The z value to the right is represented as:

[tex]P(Z > z)[/tex]

So, the probability is represented as:

[tex]P(Z > z) = 0.05[/tex]

From z table, the z value that satisfies the above probability is:

[tex]z = 1.645[/tex]

[tex]z = 1.6[/tex] --- approximated

Answer:

function ar true in the mach on which

Answer:

i think three one is right answer...

Answer:

2.-P = 0.38

3.-P [ Lb | Wt ]  =  0.788

Step-by-step explanation:

1.-Probability of choosing any box is, 1/3. So the probability of choosing the lucky box is 1/3

Let´s say the lucky box is the number 2 box  ( that consideration does not in any way change the problem generality)

Then we have

p₁ probability of choosing box  1 is 1/3   p₁´ Probability of win ticket is  0.12

p₂ probability of choosing box 2 is 1/3  p₂´Probability of win ticket is  0.90

p₃ probability of choosing box 3 is 1/3  p₃´ Probability of win ticket is  0.12

Then

P (of choosing a winning ticket is) = p₁*p₁´ + p₂*p₂´ +  p₃*p₃´

P  =  1/3*0.12 + 1/3*0.9 + 1/3*0.12

P  =  0.04 + 0.3 + 0.04

P = 0.38

3.- if I draw a winning ticket what is the probability it came from Lucky box

According to Bayes theorem

P [ Lb | Wt ]  =   P(Lb) * P[ Wt|Lb]/ P(Wt)

P(Lb) = 1/3  =  0.33333

P[Wt|Lb]  = 0.9

P(Wt) = 0.38

Then By substitution

P [ Lb | Wt ]  =  0.333 *  0.9 / 0.38

P [ Lb | Wt ]  =  0.788

Answer:

a) 1186

b) Between 1031 and 1493.

c) 160

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.

Normally distributed with mean of 1262 and a standard deviation of 118.

This means that [tex]\mu = 1262, \sigma = 118[/tex]

a) Determine the 26th percentile for the number of chocolate chips in a bag. ​

This is X when Z has a p-value of 0.26, so X when Z = -0.643.

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

[tex]-0.643 = \frac{X - 1262}{118}[/tex]

[tex]X - 1262 = -0.643*118[/tex]

[tex]X = 1186[/tex]

(b) Determine the number of chocolate chips in a bag that make up the middle 95% of bags.

Between the 50 - (95/2) = 2.5th percentile and the 50 + (95/2) = 97.5th percentile.

2.5th percentile:

X when Z has a p-value of 0.025, so X when Z = -1.96.

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

[tex]-1.96 = \frac{X - 1262}{118}[/tex]

[tex]X - 1262 = -1.96*118[/tex]

[tex]X = 1031[/tex]

97.5th percentile:

X when Z has a p-value of 0.975, so X when Z = 1.96.

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

[tex]1.96 = \frac{X - 1262}{118}[/tex]

[tex]X - 1262 = 1.96*118[/tex]

[tex]X = 1493[/tex]

Between 1031 and 1493.

​(c) What is the interquartile range of the number of chocolate chips in a bag of chocolate chip​ cookies?

Difference between the 75th percentile and the 25th percentile.

25th percentile:

X when Z has a p-value of 0.25, so X when Z = -0.675.

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

[tex]-0.675 = \frac{X - 1262}{118}[/tex]

[tex]X - 1262 = -0.675*118[/tex]

[tex]X = 1182[/tex]

75th percentile:

X when Z has a p-value of 0.75, so X when Z = 0.675.

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

[tex]0.675 = \frac{X - 1262}{118}[/tex]

[tex]X - 1262 = 0.675*118[/tex]

[tex]X = 1342[/tex]

IQR:

1342 - 1182 = 160

Answer:

(a)[tex]0.15731[/tex]

(b)0.02275

Step-by-step explanation:

We are given that

Mean=0

Standard deviation=0.5 g

True weight of a sample=166 g

Let X denote the normal random variable  with mean =166+0=166

(a)

P(166.5<X<167.5)

=[tex]P(\frac{166.5-166}{0.5}<\frac{X-\mu}{\sigma}<\frac{167.5-166}{0.5})[/tex]

=[tex]P(1<Z<3)[/tex]

=[tex]P(Z<3)-P(Z<1)[/tex]

[tex]=0.99865-0.84134[/tex]

[tex]=0.15731[/tex]

(b)

[tex]P(X>167)=P(Z>\frac{167-166}{0.5})[/tex]

[tex]=P(Z>2)[/tex]

[tex]=1-P(Z<2)[/tex]

[tex]=1-0.97725[/tex]

[tex]=0.02275[/tex]

So a Quadratic function,A quadratic function is one of the form f(x) = ax2 + bx + c, where a, b, and c are numbers with a not equal to zero

Answer:

467 muffins

Step-by-step explanation:

143 + 211 + 113 = 467

Answer:

y=7x+2

Step-by-step explanation:

In this form of an equation (y=mx+b), m is the slope of the line and b is the y-intercept.

So, since the slope (m) is 7 and the y-intercept (b) is 2, the equation is:

y=7x+2

Answer:

The p-value of the test is 0.0066 < 0.05, which means that there is sufficient evidence at the 0.05 significance level to conclude that the mean salary differs from $39,385

Step-by-step explanation:

The average salary for public school teachers for a specific year was reported to be $39,385. Test if the mean salary differs from $39,385

At the null hypothesis, we test if the mean is of $39,385, that is:

[tex]H_0: \mu = 39385[/tex]

At the alternative hypothesis, we test if the mean differs from this, that is:

[tex]H_1: \mu \neq 39385[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

39385 is tested at the null hypothesis:

This means that [tex]\mu = 39385[/tex]

A random sample of 50 public school teachers in a particular state had a mean of $41,680, and the population standard deviation is $5975.

This means that [tex]n = 50, X = 41680, \sigma = 5975[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{41680 - 39385}{\frac{5975}{\sqrt{50}}}[/tex]

[tex]z = 2.72[/tex]

P-value of the test and decision:

The p-value of the test is the probability that the sample mean differs from 39385 by at least 2295, which is P(|Z| > 2.72), which is 2 multiplied by the p-value of Z = -2.72.

Looking at the z-table, Z = -2.72 has a p-value of 0.0033

2*0.0033 = 0.0066

The p-value of the test is 0.0066 < 0.05, which means that there is sufficient evidence at the 0.05 significance level to conclude that the mean salary differs from $39,385

The work is simply the dot product of the force and displacement (which I assume are given in Newtons and meters, respectively):

W = F • d

W = (5i + 3j - 2k) N • ((4i - j + 3k) m - (j + k) m)

W = (5i + 3j - 2k) • (4i - 2j + 2k) Nm

W = (20 - 6 - 4) Nm

W = 10 J

Answer:

0.4444 = 44.44% probability that the sum of the two numbers is greater than 3 but less than 7.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

A number is selected at random from each of the sets {2,3,4} and {1, 3, 5}.

The possible values for the sum are:

2 + 1 = 3

2 + 3 = 5

2 + 5 = 7

3 + 1 = 4

3 + 3 = 6

3 + 5 = 8

4 + 1 = 5

4 + 3 = 7

4 + 5 = 9

Find the probability that the sum of the two numbers is greater than 3 but less than 7?

​4 of the 9 sums are greater than 3 but less than 7. So

[tex]p = \frac{4}{9} = 0.4444[/tex]

0.4444 = 44.44% probability that the sum of the two numbers is greater than 3 but less than 7.

Answer:

90 cause 90 times 10 is 900 and 10% times 10 is 100%

Step-by-step explanation:

Answer: 90

Step-by-step explanation: 900 × .10 = 90

Answer:

The point of intersection is [tex]( \frac{-1\pm\sqrt{5}}{2}, 0)[/tex]

Step-by-step explanation:

f(x) = 2x^2 + 3x - 3 and g(x) = - x^2

By equating them

2x^2 + 3x - 3 = -x^2

3x^2 + 3 x - 3 =  0

x^2 + x - 1 = 0

[tex]x^2 +x - 1 = 0 \\\\x = \frac{-1\pm\sqrt{5}}{2}[/tex]

Answer:

Step-by-step explanation:

two points are (-5,-2) and (-1,3)

slope=(3-(-2))/(-1-(-5))=(3+2)/(-1+5)=5/4

Answer:

$4.50

Step-by-step explanation:

Use the mean formula: mean = sum of elements / number of elements

Let x represent the cost of the fifth book, and solve for x:

mean = sum of elements / number of elements

3.25 = (11.75 + x) / 5

16.25 = 11.75 + x

4.5 = x

So, the cost of the fifth book was $4.50

Answer:

a simple random sample (SRS).

Step-by-step explanation:

In Statistics, sampling can be defined as a process used to collect or select data (objects, observations, or individuals) from a larger statistical population using specific procedures.

There are various types of sampling used by researchers and these are;

1. Systematic sampling.

2. Convenience sampling.

3. Stratified sampling.

4. Cluster sampling.

5. Random sampling.

Random sampling also referred to as simple random sample (SRS) involves randomly selecting a subset of a larger population.

In this scenario, an elected government official randomly selected five schools at random from the 20 schools in her area and then interviews each of the teachers in those five schools, in order to get their opinions about voting. Thus, the government official is using a simple random sample (SRS).

Answer:

Step-by-step explanation:

because these are similar triangles, that is, one is a bigger of smaller version of the other, then we know, that the bigger triangle is just 2 times bigger than the smaller,  or   2x of any side of the small one

sooo   2(20) =40  

so we know that side n of the bigger triangle is 40

Given:

The graph of a line.

To find:

The equation for the given line.

Solution:

From the given graph, it is clear that the line passes through the points (0,-5) and (5,0). So, the equation of the line is:

[tex]y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]

[tex]y-(-5)=\dfrac{0-(-5)}{5-0}(x-0)[/tex]

[tex]y+5=\dfrac{5}{5}(x)[/tex]

[tex]y+5=x[/tex]

Subtract 5 from both sides.

[tex]y+5-5=x-5[/tex]

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

Therefore, the equation of the given line is [tex]y=x-5[/tex].

Answer:

[tex]P(head) = 0.5600[/tex]

Step-by-step explanation:

Given

[tex]n = 500[/tex] -- number of toss

[tex]head = 280[/tex] --- outcomes of head

See comment

Required

Empirical probability of head

This is calculated as:

[tex]P(head) = \frac{n(head)}{n}[/tex]

[tex]P(head) = \frac{280}{500}[/tex]

[tex]P(head) = 0.5600[/tex]

Answer:

3, 6, 11, 18, 27

Step-by-step explanation:

hope it helps

Answer:

Step-by-step explanation:

A). Volume of a rectangular prism = Length × Width × Height

                                                        = lwh

1). Volume of a rectangular prism if the measures of the sides are,

    Length (l) = 9 cm

    Width (w) = 4 cm                                              

    Height (h) = 3 cm                                            

    Therefore, volume = lwh

                                   = 9 × 4 × 3

                                   = 108 cm³

2). Length = 10 cm

     Width = 7 cm

     Height = 15 cm

     Volume = lwh

                   = 10 × 7 × 15

                   = 1050 cm³

3). Length = 14 cm

    Width = 10 cm

    Height = 9 cm

    Volume = 14 × 10 × 9

                  = 1260 cm³

B. Volume of a cube = (Side)³

4). If the measure of one side = 12 cm

    Volume of the cube = (12)³

                                      = 1728 cm³

5). If the measure of one side = 6 cm

   Volume of the cube = (6)³

                                     = 216 cm³

Answer:

72 is 6% of 1200.

Step-by-step explanation:

Multiply 72 by 100.

72*100

Then divide the number by 6

(72*100)/6

You should get 1200.

9514 1404 393

Answer:

Step-by-step explanation:

1. The various goals can be met without filling the theater. This fact means there is a range of possibilities for each of the answers. However, we take the wording, "because of the demand for tickets ..." to mean demand is high and the theater will be sold out.

Since two children's tickets will be sold for each adult ticket sold, the number of children's tickets is 2/3 of the total.

  children's tickets = 2/3 × 120 = 80

__

2. The remaining 40 tickets will be adult tickets.

  40 adult tickets will be sold.

__

3. The total revenue must be at least $1800. If we allow 'd' tickets to be sold at a discount, then we can find the limits on d using the inequality ...

  24(40-d) +24(0.75)d +12(80) ≥ 1800 . . . . revenue from ticket sales

  -6d ≥ -120 . . . . . . . . . . . . . . . . . . . collect terms, subtract 1920

  d ≤ 20 . . . . . . . . . . divide by -6

  At least 10 and at most 20 adult tickets can be sold with a discount.

("At least 10" comes from the problem requirements.)

Answer:

D. <S, <R, <T

Step-by-step explanation:

Recall: On a triangle, the bigger an angle measure the longer the side opposite it and vice versa.

In ∆RST,

The longest side, SR = 22, is opposite to <T

Therefore, <T is the biggest angle.

Medium side, ST = 21, is opposite to <R, therefore,

<R is the medium angle measure

The smallest angle measure <S is opposite to the shortest side, RT.

Angels I'm order form the smallest to largest will be:

<S, <R, <T

9514 1404 393

Answer:

  4.1

Step-by-step explanation:

x is the short leg of a right triangle with hypotenuse 8.8 cm and longer leg 7.8 cm. Its measure is found using the Pythagorean theorem:

  x^2 +7.8^2 = 8.8^2

  x^2 = 77.44 -60.84 = 16.60

  x = √16.6

  x ≈ 4.1