Define: stratified random sample a) population is divided into similar groups and a SRS is chosen from each group. b) gives each member of the population a known chance to be selected. c) people who choose themselves for a sample by responding to a general appeal. d) the explanatory variable(s) in an experiment. e) directly holding extraneous factors constant. f) every possible sample of a given size has the same chance to be selected. g) using extraneous factors to create similar groups. h) successively smaller groups are selected within the population in stages. i) choosing the individuals easiest to reach.

Answer:

it is the 2nd option

Step-by-step explanation:

Answer:

C. 28

Step-by-step explanation:

40% + 30% = 70%

70% of 40 students

0.70 x 40 = 28

Let me know if this helps!

1. H

2. A

3. E

4. C

I have to type extra words to turn this in so basically I just found the slop of the line then matched it with the letters...

Around 4 times, maybe 3

Step-by-step explanation:

there's 2 red 3s and there's 52 cards in a deck. so u have a 2/52 chance to get a red 3 so its about a 4/104 chance to get a red 3 if u draw 1 card 100 times

In a Young's double-slit experiment, the center of a bright fringe occurs wherever waves from the slits differ in phase by a multiple of λ/2.

In Young's double-slit experiment, a coherent light source, such as a laser, is passed through two narrow slits, creating two sources of waves that interfere with each other. When the waves from the two slits meet, they create an interference pattern of bright and dark fringes on a screen placed behind the slits.

The bright fringes occur when the waves from the two slits reinforce each other constructively, resulting in a bright spot. The central bright fringe is the brightest and occurs at the center of the pattern. This is because at the center, the waves from both slits travel the same distance to the screen.

For the waves to interfere constructively at the center of the pattern, they must be in phase. In other words, the waves from the two slits must have a phase difference of an integer multiple of the wavelength (λ) of the light. Mathematically, this phase difference can be expressed as an integer multiple of λ/2.

Therefore, the correct answer is D) λ/2, where λ represents the wavelength of the light used in the experiment.

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(27.26604445073)

this answer for this question

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Answer:

Let's solve your equation step-by-step.

−2 = 3 + b / 4

Step 1: Simplify both sides of the equation.

−2 = 3 + b / 4

−2 = 3 + 1 / 4b

−2 = 1 / 4b + 3

Step 2: Flip the equation.

1 / 4b + 3 = −2

Step 3: Subtract 3 from both sides.

1 / 4b + 3 − 3 = −2 − 3

1 / 4b = −5

Step 4: Multiply both sides by 4.

4 * ( 1 / 4b ) = ( 4 ) * ( −5 )

b = −20

Answer:

b = −20

<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3

Answer:

-3.2

Step-by-step explanation:

Answer:

The percentage discount is 37.5

Same I also need help ;-;

Answer:

10 days

Step-by-step explanation:

Mogaka and Ondiso working together can do a piece of job in 6 days. Mogaka working alone takes 5 days longer than Ondiso. How many days does it take Ondiso to do the work alone?

Let us represent :

The number of days

Mogaka worked alone = x

Ondiso worked alone = y

Total days worked together = T

Mogaka and Ondiso working together can do a piece of job in 6 days.

Hence,

1/x + 1/y = 1/T

Mogaka working alone takes 5 days longer than Ondiso.

x = y + 5

Therefore:

1/y + 5 + 1/y = 1/6

Multiply all through by (y+5)(y)

= y + y + 5 = (y+5)(y)/6

= 2y + 5/1 = (y+5)(y)/6

Cross Multiply

6( 2y + 5) = (y+5)(y)

12y + 30 = y² + 5y

= y² + 5y - 12y - 30 = 0

= y² - 7y - 30 = 0

Factorise

= y² +3y - 10y - 30 = 0

y(y + 3) - 10(y + 3) = 0

(y + 3)(y -10)= 0

y + 3 = 0, y = -3

y - 10 = 0

y = 10 days

Note that

The number of days Ondiso worked alone = y

Hence, it takes 10 days for Ondiso to work alone

The probability distribution of the random variable Y = X²+1 is;

P(Y=1) = 81/256,

P(Y=2) = 243/1024,

P(Y=5) = 27/256,

P(Y=10) = 1/64,

P(Y=17) = 1/256

The probability distribution of the random variable Y = X² + 1 can be obtained as follows;

Explanation:

We know that the binomial probability distribution function is given by;

P(X=k) = (nCk)pk(1−p)n−k

Here, X is a binomial random variable with parameters;

n = 4 and p = 1/4

For X = 0;

P(X=0) = (4C0)(1/4)0(3/4)4−0

=81/256

For X = 1;

P(X=1) = (4C1)(1/4)1(3/4)4−1

=243/1024For X = 2;

P(X=2) = (4C2)(1/4)2(3/4)4−2

=27/256

For X = 3;

P(X=3) = (4C3)(1/4)3(3/4)4−3

=1/64

For X = 4;

P(X=4) = (4C4)(1/4)4(3/4)4−4

=1/256

Now we find the distribution function of Y;

P(Y=y) = P(X²+1=y)

Using X=0;

Y = X²+1

= 0+1

= 1;

P(Y=1) = P(X²+1=1)

= P(X=0)

= 81/256

Using X=1;

Y = X²+1

= 1+1

= 2;

P(Y=2) = P(X²+1=2)

= P(X=0)

= 243/1024

Using X=2;

Y = X²+1

= 4+1

= 5;

P(Y=5) = P(X²+1=5)

= P(X=2)

= 27/256

Using X=3;

Y = X²+1

= 9+1

= 10;

P(Y=10) = P(X²+1=10)

= P(X=3)

= 1/64

Using X=4;

Y = X²+1

= 16+1

= 17;

P(Y=17) = P(X²+1=17)

= P(X=4)

= 1/256

Therefore, the probability distribution of the random variable

Y = X²+1 is;

P(Y=1) = 81/256,

P(Y=2) = 243/1024,

P(Y=5) = 27/256,

P(Y=10) = 1/64,

P(Y=17) = 1/256

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Answer:

The significance of the sample is that at it is statistically significant at 0.01 level ( i.e. of observing the sample < 0.01 )

Step-by-step explanation:

The sample observation which is 121 mothers that take vitamin supplements have male babies with mean weight of : 3.67 kg

while the National average birth weight = 3.39 kg

probability of observing such a sample = 0.0015

Hence the significance of the sample is that at it is statistically significant at 0.01 level ( i.e. of observing the sample < 0.01 )

Answer:

0.55

Step-by-step explanation:

11 (the time it lands on heads) /20 (the number of times it was flipped) = 0.55

Answer:

PEI famous potato is a better deal

Step-by-step explanation:

Given that :

PEI potato :

25kg costs $12.95

Price per kg :

$12.95 / 25 = $0.518 per kg

IDAHO Potato :

10kg costs $5.78

Price per kg:

$5.78 / 10

= $0.578 per kg

0.518 < 0.578

Hence, PEI famous potato is a better deal

Answer:

752.884 cubic feet

Step-by-step explanation:

Brainliest?

Applying the formula, it is found that the flow rate is of 753 cubic feet per second.

The flow rate is modeled by:

[tex]Q = 3.367lh^{\frac{3}{2}}[/tex]

[tex]Q = 3.367l\sqrt{h^3}[/tex]

In which the parameters are:

In this problem:

Then:

[tex]Q = 3.367l\sqrt{h^3}[/tex]

[tex]Q = 3.367(20)\sqrt{5^3}[/tex]

[tex]Q = 753[/etx]

The rate is of 753 cubic feet per second.

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9514 1404 393

Answer:

  x = 2

Step-by-step explanation:

To find g(x), we can start with the inverse of f(x).

  f(y) = x . . . . . . . solve this to find f^-1(x)

  3y -2 = x

  3y = x +2 . . . . add 2

  y = (x +2)/3 = f^-1(x) . . . . divide by 3

__

Now, we can find g(x):

  f^-1(f(g(x)) = g(x)

  f^-1(6x -2) = ((6x -2) +2)/3 = g(x)

  6x/3 = g(x) = 2x

__

Now, we want g(f(x)) = 8

  g(3x -2) = 8

  2(3x -2) = 8

  6x -4 = 8

  6x = 12

  x = 2 . . . . makes g(f(x)) = 8

No, Sammy's answer of 6 tenths is not correct because the answer is 7 tenths.

To know if Sammy's answer is correct, we will perform subtraction:

8 tenths - 2 hundredths

In this case, we wil convert 8 tenths to hundredths by multiplying it by 10:

8 tenths = 8 * 10

8 tenths = 80 hundredths

==> 80 hundredths - 2 hundredths

==> 78 hundredths

Converting 78 hundredths back to tenths, we divide by 10:

==> 78 hundredths / 10

==> 7.8 tenths.

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Answer:

Our radius is already given, 8.

8 x 3.14 x 2 = 50.24cm <-------- perimeter/circumference

8^2 x 3.14

64 x 3.14 = 200.96cm2 <------- area

Formula of a circumference:

2πr

2 x pie x radius (pie can be used as 22/7 or 3/4 most likely 3.14)

Formula of an area of a Circle:

πr^2

pie x radius squared (pie can be used as 22/7 or 3.14)

Step-by-step explanation:

b=books

3b[tex]\leq[/tex]23

[tex]b\leq 23/3[/tex]

[tex]b\leq 7.67[/tex]

L=lesson

25L[tex]\leq[/tex]150

L[tex]\leq[/tex]6

Hope that helps :)

Answer: a)7, B)8

Step-by-step explanation:

Problem a) If Kai wants to buy just one poster that costs 2 dollars, he has 25-2=23 dollars left. If each book is 3 dollars, then he  can buy 23/3 books. The inequality that results is that if b=#ofbooks, then b< or = (25-2)/3, because you cant buy a book for 2 and a half dollars, hence the less than. 23/3 is 7 r2. We get that b< or = to 7 2/3. However, he can't buy 2/3 of a book, so 7. The final inequality we get is that 2+3b<=25

Problem 2) She spends 50 initially, so 200-50=150 dollars left. Thus the number of lessons, or n, cover the rest of the money. Using the same thory as above, the final inequality is 50+25n<=200. n=8.

In the system of linear equations -y = 2 kx - y = k,

(a) The augmented matrix can be reduced to row-echelon form by performing row operations.

(b) The system has (a) no solutions: None, (b) exactly one solution: x = 2k, y = k (in terms of k).

(c) infinitely many solutions: x = t, y = 0 (in terms of t) when k = 0.

(a) To reduce the augmented matrix for the system to row-echelon form, we can perform row operations.

Starting with the augmented matrix:

[ -1 | 2k ]

[ -1 | k ]

We can perform the following row operations to obtain row-echelon form:

Replace R2 with R2 + R1:

[ -1 | 2k ]

[ -2 | 3k ]

Now, the augmented matrix is in row-echelon form.

(b)To find the values of k for different cases, we can observe the row-echelon form:

[ -1 | 2k ]

[ 0 | k ]

From the row-echelon form, we can conclude the following:

(i) If k ≠ 0, then the system has a unique solution. The solution is x = 2k and y = k.

(ii) If k = 0, then the system has infinitely many solutions. The solution can be expressed as x = t and y = 0, where t is a parameter.

(iii) There are no values of k for which the system has no solutions.

Therefore, the system has (a) no solutions: None, (b) exactly one solution: x = 2k, y = k (in terms of k), and (c) infinitely many solutions: x = t, y = 0 (in terms of t) when k = 0.

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Answer:

3 x -10.5

Step-by-step explanation:

The problem says "each for -10.50." That means every entry has a change of -10.5.

We know there are 3 entries so we are going to multiply 3 x -10.5 (The expression is the answer, not the actual answer.)

Answer:

X=1.8

Step-by-step explanation:

Step one: 5 times 1.8 equals 9.

Step two: 9+2=11

a) To find the general solution of the given differential equation, a power series centered at x=0 is used, and the first five nonzero terms of each power series are determined.

b) The solution to the initial value problem y' = √(1-y^2), y(0) = 0, is shown to be y = sin(x).

c) The coefficients up to the term in x^7 are found for a power series solution of the initial value problem y' = √(1-y^2), y(0) = 0.

a) To find the general solution y = yc + yp of the given differential equation:

y'' + x^2 y' + 2xy = 5 - 2x + 10x^3,

we can first find the complementary solution yc by assuming a power series of the form y = ∑(n=0 to ∞) a_n x^n. Substituting this series into the differential equation and equating coefficients of like powers of x, we can determine the values of the coefficients a_n. However, for simplicity, we will only consider the first five nonzero terms of the power series.

Let's write the power series for yc:

yc = a_0 + a_1 x + a_2 x^2 + a_3 x^3 + a_4 x^4 + ...

Differentiating twice with respect to x, we get:

y' = a_1 + 2a_2 x + 3a_3 x^2 + 4a_4 x^3 + ...

y'' = 2a_2 + 6a_3 x + 12a_4 x^2 + ...

Substituting these series into the differential equation, we have:

(2a_2 + 6a_3 x + 12a_4 x^2 + ...) + x^2(a_1 + 2a_2 x + 3a_3 x^2 + 4a_4 x^3 + ...) + 2x(a_0 + a_1 x + a_2 x^2 + a_3 x^3 + a_4 x^4 + ...) = 5 - 2x + 10x^3

To equate coefficients, we match the powers of x on both sides of the equation:

For the term without x:

2a_2 + a_0 = 5

For the term with x:

6a_3 + 2a_2 + a_1 = -2

For the term with x^2:

12a_4 + 3a_3 + 2a_1 + a_2 = 0

For the term with x^3:

4a_4 + 4a_2 + a_3 = 10

For the term with x^4:

a_4 = 0 (no coefficient on the right-hand side)

Solving this system of equations will give us the values of a_0, a_1, a_2, a_3, and a_4. Since we are only interested in the first five nonzero terms of the power series, we will truncate the series at the fifth term.

b) To show that y = sin(x) is the solution to the initial value problem y' = √(1-y^2), y(0) = 0:

We can differentiate y = sin(x) to obtain y' = cos(x). Substituting this into the differential equation, we have:

cos(x) = √(1 - sin^2(x))

Using the trigonometric identity sin^2(x) + cos^2(x) = 1, we simplify the equation to:

cos(x) = √(cos^2(x))

Taking the positive square root, we have:

cos(x) = cos(x)

This confirms that y = sin(x) satisfies the differential equation y' = √(1-y^2).

c) To find a power series solution for the initial value problem y' = √(1-y^2), y(0) = 0, we assume a power series of the form y = ∑(n=0 to ∞) a_n x^n. Substituting this series into the differential equation and equating coefficients, we can determine the values of the coefficients a_n up to the term in x^7.

Let's write the power series for y:

y = a_0 + a_1 x + a_2 x^2 + a_3 x^3 + a_4 x^4 + a_5 x^5 + a_6 x^6 + a_7 x^7 + ...

Differentiating y with respect to x, we get:

y' = a_1 + 2a_2 x + 3a_3 x^2 + 4a_4 x^3 + 5a_5 x^4 + 6a_6 x^5 + 7a_7 x^6 + ...

Substituting these series into the differential equation, we have:

a_1 + 2a_2 x + 3a_3 x^2 + 4a_4 x^3 + 5a_5 x^4 + 6a_6 x^5 + 7a_7 x^6 + ... = √(1 - (a_0 + a_1 x + a_2 x^2 + a_3 x^3 + a_4 x^4 + a_5 x^5 + a_6 x^6 + a_7 x^7 + ...)^2)

Simplifying this equation and equating coefficients of like powers of x, we can determine the values of the coefficients a_n up to the term in x^7.

To find the coefficients up to the term in x^7, you will need to perform the substitution and equate coefficients. It will involve expanding the square root and equating coefficients of each power of x from 0 to 7 on both sides of the equation.

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Answer: 59

Step-by-step explanation:

Given

2b³+5 and b=3 ⇒ 2b³+5=2(3)³+5

Simplify exponents

 2(3)³+5

=2(3×3×3)+5

=2×27+5

Multiplication

=54+5

Addition

=59

Hope this helps!! :)

Please let me know if you have any questions

Answer:

The prism is 3 by 3 by 1.5.

Step-by-step explanation:

The prism has a length x and a width x. Since it is a square at the base both length and width are the same amount x. The height is "half the length of one edge of the base". Since the base is x, this makes it 1/2x.

The volume's prism is found using V = l*w*h. Substitute and simplify.

13.5 = x*x*1/2x

13.5 = 1/2 x^3

27 = x^3

3 = x

The prism is 3 by 3 by 1.5.

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The average salary for assistant professors is $80,776.0. The 95% confidence interval for B1 cannot be determined. The interpretation of ß1, ß2, and average salaries of associate and full professors cannot be provided due to missing coefficients.

(a) The average salary for assistant professors can be determined by the coefficient B1, which is reported as $80,776.0 in the regression model.

(b) To calculate a 95% confidence interval for B1, we need the standard error associated with B1. Unfortunately, the standard error is not provided in the given information, so we cannot determine the confidence interval or assess its statistical significance.

(c) The coefficient B1 represents the average difference in salary between associate professors and assistant professors. However, since the given information does not provide the coefficient for "Asst Prof," we cannot estimate the average salary of associate professors based on the given model.

(d) The coefficient B2 represents the average difference in salary between full professors and assistant professors. However, since the given information does not provide the coefficient for "Prof," we cannot estimate the average salary of full professors based on the given model.

(e) We cannot estimate the model yi = Bo + B11(AssocProf) + B21(Prof) + B31(Asst Prof) + u because the variable "Asst Prof" is collinear with the other two binary indicator variables (AssocProf and Prof). Collinearity occurs when predictor variables are highly correlated, leading to unreliable estimates of their coefficients.

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Answer:

The answer is x < 4

Step-by-step explanation:

1) Subtract 6 from both sides.

[tex]4x < 22 - 6[/tex]

2) Simplify 22 - 6 to 16.

[tex]4x < 16[/tex]

3) Divide both sides by 4.

[tex]x < \frac{16}{4} [/tex]

4) Simplify 16/4 to 4.

[tex]x < 4[/tex]

Therefor, the answer is x < 4.

The work shown is not correct. The correct result of (11 + 2i) - (3 - 10i) is 8 + 12i.

To evaluate the given expression, we need to subtract the real parts and the imaginary parts separately.

Real part:

11 - 3 = 8

Imaginary part:

2i - (-10i) = 2i + 10i = 12i

Combining the real and imaginary parts, we get the correct result:

8 + 12i

So, the correct answer is 8 + 12i, not 8 - 8i as shown in the work.

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