A bag contains five white balls and four black balls. Your goal is to draw two black balls. You draw two balls at random. Once you have drawn two balls, you put back any white balls, and redraw so that you again have two drawn balls. What is the probability that you now have two black balls? (Include the probability that you chose two black balls on the first draw.)

Correct question is;

Find the surface area of that part of the plane 10x + 7y + z = 4 that lies inside the elliptic cylinder x²/25 + y²/9 = 1

Answer:

A(S) = 15π√150

Step-by-step explanation:

We are given;

10x + 7y + z = 4

Making z the subject, we have;

z = 4 - 10x - 7y

Now, area of the surface as part of z = f(x, y) is;

A(S) = ∫∫√[(∂f/∂x)² + (∂f/∂y)² + 1]dA

From z = 4 - 10x - 7y,

∂f/∂x = -10

∂f/∂y = -7

Thus;

A(S) = ∫∫√[(-10)² + (-7)² + 1]dA

A(S) = √150 ∫∫dA

Where ∫∫dA is the elliptical cylinder

From the general form of an area enclosed by an ellipse with the formula;

x²/a² + y²/b² = 1 and comparing with

x²/25 + y²/9 = 1, we have;

a = 5 and b = 3

So, area of elliptical cylinder = πab

Thus;

A(S) = √150 × π(5 × 3)

A(S) = 15π√150

The surface area of that part of the plane 10x+7y+z=4 that lies inside the elliptic cylinder [tex]\dfrac{x^2}{25}+\dfrac{y^2}{9}=1[/tex] is [tex]15\pi\sqrt{150}[/tex] and this can be determined by using the given data.

Given :

Equation (1) can also be written as:

z = 4 - 10x - 7y      ---- (3)

The surface area is given by the equation:

[tex]\rm A(s) = \int \int \sqrt{(\dfrac{\delta f}{\delta x})^2+(\dfrac{\delta f}{\delta y})^2+1}\;dA[/tex]     --- (4)

[tex]\dfrac{\delta f}{\delta x} = -10[/tex]

[tex]\dfrac{\delta f}{\delta y} = -7[/tex]

Now, substitute the known values in the equation (4).

[tex]\rm A(s) = \int \int \sqrt{(10)^2+(7)^2+1}\;dA[/tex]  

[tex]\rm A(s) = \sqrt{150} \int \int\;dA[/tex]  

Now the area enclosed by an ellipse is given by:

[tex]\dfrac{x^2}{25}+\dfrac{y^2}{9}=1[/tex]

[tex]\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}=1[/tex]

By comparing the above equation:

a = 5

b = 3

The area is given by:

[tex]\rm A(s)=\sqrt{150}\times \pi(5\times 3)[/tex]

[tex]\rm A(s) = 15\pi \sqrt{150}[/tex]

For more information, refer to the link given below:

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Answer: Find answer in the attachment

Step-by-step explanation:

Answer:

Below

Step-by-step explanation:

First method:

● f(x)= (x^3-2x+1)×(x-3)

● f'(x)= (x^3-2x+1)' ×(x-3) + (x^3-2x+1)×(x-3)'

●f'(x)= (3x^2-2)×(x-3) + (x^3-2x+1) × 1

●f'(x) = 3x^3-9x^2-2x+6 + x^3-2x+1

● f'(x)= 4x^3-9x^2-4x+7

■■■■■■■■■■■■■■■■■■■■■■■■■■

Second method:

●f(x) = (x^3-2x+1)×(x-3)

●f(x) = x^4-3x^3 -2x^2+6x+x-3

●f(x) = x^4-3x^3-2x^2+7x-3

●f'(x) = 4x^3-9x^2-4x+7

We got the same result using both methods.

Answer:

65%

Step-by-step explanation:

If 14 are male, then 26 are female.

To find the percent female, divide the number of females by the total.

26/40 = 0.65

So, the percentage of the class that is female is 65%

Answer:

C. 65%

Step-by-step explanation:

We know that of the 40 total students, 14 are male, which means the remaining students are female.

To find how many are female, we subtract 14 from 40:

40 - 14 = 26 females

Percentage is simply a part divided by a whole, multiplied by 100. Here, the "part" is the number of females, which is 26. The "whole" is the total number of students, which is 40. So, we have:

(26 / 40) * 100 = 65

The answer is thus C, 65%.

~ an aesthetics lover

Answer:

This is a geometric progresion that begins with 1 and each term is 1/3 the preceeding term

   Let Pn represent the nth term in the sequence

   Then Pn = (1/3)^n-1

   From this P14 = (1/3)^13 = 1/1594323

5. The sum of the first n terms of a GP beginning a with ratio r is given by

   Sn = a* (r^n+1 - 1)/(r - 1)

   With n = 10, a = 1 and r = 1/3, S10 = ((1/3)^11 - 1)/(1/3 - 1) = 1.500

Answer:

Step-by-step explanation:

Given the expression in rectangular coordinate as x²+y²−4x=0, in order to write the given expression in polar coordinates, we need to write the value of x and y as a function of (r, θ).

x = rcosθ and y = rsinθ.

Substituting the value of x and y in their polar form into the given expression we have;

x²+y²−4x=0

( rcosθ)²+( rsinθ)²-4( rcosθ) = 0

Expand the expressions in parenthesis

r²cos²θ+r²sin²θ-4rcosθ = 0

r²(cos²θ+sin²θ)-4rcosθ = 0

From trigonometry identity, cos²θ+sin²θ =1

The resulting equation becomes;

r²(1)-4rcosθ = 0

r²-4rcosθ = 0

Add 4rcosθ to both sides of the equation

r²-4rcosθ+4rcosθ = 0+4rcosθ

r² = 4rcosθ

Dividing both sides by r

r²/r = 4rcosθ/r

r = 4cosθ

Hence the correct equation in polar coordinates is r = 4cosθ

Answer:

The product decreases 2022.

Step-by-step explanation:

(x + 1)(y - 1) = xy + 2020

xy - x + y - 1 = xy + 2020

-x + y = 2021

(x - 1)(y + 1) = xy + x - y - 1

  + 2021   =       -x + y

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

(x - 1)(y + 1) + 2021 = xy - 1

(x - 1)(y + 1) = xy - 2022

The product decreases 2022.

Answer:

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

Step-by-step explanation:

Substitute the point into the equation and see if it is true

(8,-2)

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

    -2+2 = 2(8+8)

    0 = 2(16)

False

(2) y-2=2(x-8)

  -2-2 = 2(8-8)

  -4 =2 (0)

  False

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

  -2+2 = 2( 8-8)

  0 = 2(0)

 True

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

  -2-2 = 2(8+8)

  -4 = 2(16)

False

Answer:

[tex]\boxed{y+2=2(x-8) }[/tex]

Step-by-step explanation:

[tex]x=8[/tex]

[tex]y=-2[/tex]

[tex]\sf Check \ the \ third \ option.[/tex]

[tex]-2+2=2(8-8)[/tex]

[tex]\sf Both \ sides \ must \ be \ equal.[/tex]

[tex]0=2(0)[/tex]

[tex]0=0[/tex]

Answer:

There is no sufficient evidence to support the claim

Step-by-step explanation:

From the question we are told that

     The level of significance is  [tex]\alpha = 0.05[/tex]

     The  sample proportion is  [tex]\r p = 0.08[/tex]

     The  sample size is  [tex]n = 250[/tex]

Generally for normal sampling distribution can  be used

     [tex]n * p > 5[/tex]

So  

     [tex]n* p = 250 * 0.12 = 30[/tex]

Since  

     [tex]n * p > 5[/tex] then  normal sampling distribution can  be used

The null hypothesis is  [tex]H_o : p = 0.12[/tex]

  The alternative hypothesis is  [tex]H_a : p > 0.12[/tex]

The  test statistic is evaluated as

            [tex]t = \frac{\r p - p }{ \sqrt{ \frac{p(1- p)}{n} } }[/tex]

substituting values

            [tex]t = \frac{0.08 - 0.12 }{ \sqrt{ \frac{0.12 (1- 0.12)}{250 } } }[/tex]

            [tex]t = -1.946[/tex]

The  p-value is obtained from the z  table and the value is

        [tex]p-value = P(t > -1.9462) =0.97512[/tex]

Since the [tex]p-value > \alpha[/tex]

    Then we fail to reject the null hypothesis

Hence it means there is no sufficient evidence to support the claim

Answer :

[tex] \frac{2 {x}^{3} + 7 {x}^{2} + 3x - 4}{ {x}^{3} + 3 {x}^{2} + x - 1} [/tex]

Step-by-step-explanation :

I did the explanation in the picture.

Answer:

B = 32

Step-by-step explanation:

Since this is an isosceles triangle, C is also equal to 74 degrees

 the angles of a triangle add to 180

A + B+ C = 180

74+ B + 74 = 180

148 + B = 180

B = 180-148

B =32

Answer:

Critical F value  = 4.9503

Step-by-step explanation:

Given that:

The sample size of the numerator = 7

The sample size of the denominator = 6

The degree of freedom for the numerator df = n -1

The degree of freedom for the numerator df = 7 - 1

The degree of freedom for the numerator df = 6

The degree of freedom for the denominator df = n - 1

The degree of freedom for the denominator df = 6 - 1

The degree of freedom for the denominator df = 5

The assume that the test is two tailed and using a level of significance of ∝ = 0.10

The significance level for the two tailed test = 0.10/2 = 0.05

From the standard normal F table at the level of significance of 0.05

Critical F value  = 4.9503

Answer:

$350

Step-by-step explanation:

1. Set up the equation. The sale price of $259 is 74% of the original price.

[tex]\frac{74}{100}[/tex] = [tex]\frac{259}{x}[/tex]

2. Cross multiply

74x = 25900

3. Solve

x = 350

Answer:

The answer is 55, -275, 1375, -6875......

Step-by-step explanation:

Answer:

5 and 3/32 of an inch.

Answer: a. population = "All Students"

b. 0.22

c. 0.24

Step-by-step explanation:

a. Population is the largest group of individuals having same characteristics by the researcher's point of view.

Here , the interest is  "Students study foreign language"

So, population = "All Students"

b. Let p be the pro[portion of secondary school students study a foreign language.

In a certain state 22% of secondary school students study a foreign language.

The value of proportion [tex]p_1[/tex] =- 0.22

c. A group of 100 students were selected in random sample and 24 of them study a foreign language.

The value of proportion [tex]p_2=\dfrac{24}{100}=0.24[/tex]

Answer:

1.3859

Step-by-step explanation:

The formula for Margin of Error is given as:

Margin of Error = Critical value × Standard Error

Critical value = z score

In the question, we are given a confidence interval of 95%.

Z score for a 95% confidence level is given as: 1.96

Hence, critical value = 1.96

Standard Error = σ / √n

Where n = number of samples = 98 chicken eggs

σ = Standard deviation = 7 milligrams

Standard Error = 7/√98

Standard Error = 0.7071067812

Hence, Margin of Error = Critical value × Standard Error

Margin of Error = 1.96 × 0.7071067812

Margin of Error = 1.3859292911

Therefore, the margin of error corresponding to a 95% confidence interval for the true mean cholesterol content, μ, of all such eggs is approximately 1.3859

Answer:

Step-by-step explanation:

Given vector the following vector equations OA = 13x+7y , OB = 5x+12y and CO = -15x+12y, the following expression is true about vector OA, OB and OC;

OA+OB = CO (CO is the resultant since its is moving in the opposite direction compare to OA and OB)

Also BO+OA = BA and AO+OC = AC

If OB = 5x+12y, then BO = -(5x+12y)

BO = -5x-12y (BO = -OB)

Since BO+OA = BA

BA = -5x-12y + 13x+7y

BA = -5x+13x-12y+7y

BA = 8x-5y

Similarly AO+OC = AC

Since AO = -OA and OC = -CO

-OA-CO  = AC

AC = -(13x+7y)-(-15x+12y)

AC = -13x-7y+15x-12y

AC = -13x+15x-7y-12y

AC = 2x-19y

Answer:

The question is not complete, below is the complete question:

What is meant by the term 90% confident? when constructing a confidence interval for a mean?

a. If we took repeated samples, approximately 90% of the samples would produce the same confidence interval.

b. If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the sample mean.

c. If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the true value of the population mean.

d. If we took repeated samples, the sample mean would equal the population mean in approximately 90% of the samples.

Answer:

The correct answer is:

If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the true value of the population mean.  (c)

Step-by-step explanation:

a 90% confidence level means that if repeated samples were taken, 9 out of 10 times, the confidence intervals of the sample chosen will be close to the mean (true value), which is a true representation of the population parameter. when using confidence intervals, there are always margins of allowable accuracy, and this is suggested by using standard diviations snd variances.

I attached a simple document to this answer that will give you more insight into confidence intervals used in statistics.

Answer:

(2+7) root 3 equals 9 root 3

Answer:

r = 19

Step-by-step explanation:

( r-5) /2 = ( r+2) /3

The least common denominator is 6

3/3 *( r-5) /2 = ( r+2) /3 * 2/2

3( r-5) /6 = 2( r+2) /6

Since the denominators are the same, the numerators are the same

3( r-5) = 2(r+2)

Distribute

3r -15 = 2r+4

Subtract 2r from each side

3r-2r -15 = 2r+4-2r

r-15 =4

Add 15 to each side

r-15+15 = 4+15

r = 19

Answer:

the 4 and 8 are exponents

Step-by-step explanation:

Answer:

  0 ≤ x ≤ 10

Step-by-step explanation:

The domain of f(x) is the set of values of x for which the function is defined. Here, the square root function is only defined for non-negative arguments, so we require ...

  -x^2 +10x ≥ 0

  x(10 -x) ≥ 0

The two factors in this product will both be positive only for values ...

  0 ≤ x ≤ 10 . . . . the domain of f(x)

We want to maximize [tex]x^3y^4z[/tex] subject to the constraint [tex]x+y+z=30[/tex].

The Lagrangian is

[tex]L(x,y,z,\lambda)=x^3y^4z-\lambda(x+y+z-30)[/tex]

with critical points where the derivatives vanish:

[tex]L_x=3x^2y^4z-\lambda=0[/tex]

[tex]L_y=4x^3y^3z-\lambda=0[/tex]

[tex]L_z=x^3y^4-\lambda=0[/tex]

[tex]L_\lambda=x+y+z-30=0[/tex]

[tex]\implies\lambda=3x^2y^4z=4x^3y^3z=x^3y^4[/tex]

We have

[tex]3x^2y^4z-4x^3y^3z=x^2y^3z(3y-4x)=0\implies\begin{cases}x=0,\text{ or}\\y=0,\text{ or}\\z=0,\text{ or}\\3y=4x\end{cases}[/tex]

[tex]3x^2y^4z-x^3y^4=x^2y^4(3z-x)=0\implies\begin{cases}x=0,\text{ or}\\y=0,\text{ or}\\3z=x\end{cases}[/tex]

[tex]4x^3y^3z-x^3y^4=x^3y^3(4z-y)=0\implies\begin{cases}x=0,\text{ or}\\y=0,\text{ or}4z=y\end{cases}[/tex]

Let's work with [tex]x=3z[/tex] and [tex]y=4z[/tex], for which we have

[tex]x+y+z=8z=30\implies z=\dfrac{15}4\implies\begin{cases}x=\frac{45}4\\y=15\end{cases}[/tex]

The smallest of these is C. 15/4.

Answer:

Children = 150

Students = 98

Adults = 75

Step-by-step explanation:

C + S + A = 323

5C + 7S + 12A = 2336

A = 1/2C

C = 150

S = 98

A = 75

Answer:

12.5 minutes

Step-by-step explanation:

When working together,It takes two computers 10 minutes to send out an email

It takes the slower computer 50 minutes to send out an email

Let x represent the time taken by the faster computer to do the job in its own

Therefore, the time required by the faster computer can be calculated as follows

1/x + 1/50= 1/10

Collect the like terms

1/x= 1/10-1/50

1/x= 4/50

Cross multiply both sides

4 × x = 50×1

4x=50

Divide both sides by the coefficient of x which is 4

4x/4=50/4

x= 12.5

Hence the time taken by the faster computer to finish the job on its own is 12.5 minutes

Answer:

D. a line and a point not on that line

Step-by-step explanation:

That is how you determine a plane.

The factors which determine a plane are a line and a point not on that line.

In geometry, a plane is a flat surface that extends into infinity.

In a three dimensional space, a plane can be defined by three points it contains, as long as those points are not on the same line.

Therefore, the factors which determine a plane are a line and a point not on that line.

Hence, option D is correct.

Learn more about plane here:

https://brainly.com/question/17458011

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-1.5

Step-by-step explanation:

So, you do 7.25 - 1 (because it is) and you get 6.25. Make it a fraction inton 25/4 and divide bu 75/8 (9 3/8 simplified) and you get -1.5 voila.

Answer:

x = 3/2

Step-by-step explanation:

7 1/4 = 7 + 1/4 = 28/4 + 1/4 = 29/4

9 3/8 = 9 + 3/8 = 72/8 + 3/8 = 75/8

then:

7 1/4 x = 29x/4

29x/4 - x = 75/8

29x/4 - 4x/4 = 75/8

25x/4 = 75/8

x = (75/8)/(25/4)

x = (75*4)/(8*25)

x = 300/200

x = 3/2

Checking:

(29/4)(3/2) = (29*3)(4*2) =  87/8

87/8 - 3/2 = 75/8

3/2 = 12/8

then:

87/( - 12/8 = 75/8

Answer:

(3x-5)(4x+7) / 4x + 17

Step-by-step explanation:

Rewrite the division as a fraction

12 x ^2 + x-35 / 4x+17

Factor by grouping

(3x-5)(4x+7) / 4x + 17

Hope this was the answer you were looking for