6.18 heart transplant success. the stanford university heart transplant study was conducted to determine whether an experimental heart transplant program increased lifespan. each patient entering the program was officially designated a heart transplant candidate, meaning that he was gravely ill and might benefit from a new heart. patients were randomly assigned into treatment and control groups. patients in the treatment group received a transplant, and those in the control group did not. the table below displays how many patients survived and died in each group.22 control treatment alive 4 24 dead 30 45 suppose we are interested in estimating the difference in survival rate between the control and treatment groups using a confidence interval. explain why we cannot construct such an interval using the normal approximation. what might go wrong if we constructed the confidence interval despite this problem?

Answers

Answer 1

We cannot construct a confidence interval using the normal approximation in this case because the sample sizes of the control and treatment groups are relatively small (less than 30), and the data does not meet the assumptions required for the normal approximation.

The normal approximation assumes that the data follows a normal distribution, and for sample sizes less than 30, the distribution of the sample mean may not be well approximated by a normal distribution. In addition, the normal approximation assumes that the observations are independent, which may not hold true in this study due to the nature of the treatment and control groups.

If we constructed a confidence interval despite these problems, the interval may not accurately reflect the true difference in survival rates between the control and treatment groups. The interval could be biased or too wide/narrow, leading to incorrect conclusions about the effectiveness of the heart transplant program. Therefore, it is important to use appropriate statistical methods that account for the specific characteristics of the data and study design in order to obtain reliable estimates and valid inferences.

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okkkkkkkkkkkkkkkkkkkkk
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Solve the given system of differential equations by systematic elimination.
(D − 1)x+ (D² + 1)y = 1
(D² − 1)x+ (D + 1)y = 2

(x(t), y(t)) = (e^-t/2 [-5/3cos(√47/2)t - 125/3 sin(√47/2)t]+ 20/3 cos (3t) + 20/3 sin (3t)

Answers

Given system of differential equation is(D − 1)x+ (D² + 1)y = 1 ...

(i)(D² − 1)x+ (D + 1)y = 2 ...(ii)By using systematic elimination method, we have(D²+1)(D²−1)x+(D+1)(D−1)y=D²+1×1-(D+1)×1=0Simplifying the above equation, we get(D⁴-1)x=-(D-1)y...(iii)Applying D on both sides of (iii), we get D(D⁴-1)x=-(D-1 )DyD⁵x- Dx=-(Dy-y)or D⁵x+Dy=y ... (iv)Now applying D on (i), we get(D−1)Dx+(D²+1)Dy=0or D(D²+1)y=(1-D)x ...(v)Now applying D on (ii), we get(D²−1)Dx+(D+1)Dy=0or D(D+1)x=(1+D)y ...(vi)Now, substituting the value of x and y from equations (v) and (vi) in equation (iv), we getD⁵x+(1+D)Dx=(1-D)Dy D⁵x+(1+D)Dx=-(1-D)x ...(vii) Simplifying the above equation, we getD⁶x+2D⁴x+D²x+x=0or D²(D⁴+1)x+D²x=-x ...(viii)or D²(D⁴+2)x=-xor D⁴x+2x=-xor D⁴x=-3xNow using D on both sides, we get D⁵x=-3Dxor D⁶x=-3D²x

Now, substituting the value of D²x from equation (iii) in equation (i), we get(D-1)x+(D²+1)y=1 ...(i)⇒ (D-1)x+y=1 ...(ix)Now, substituting the value of D²x from equation (iii) in equation (ii), we get(D²-1)x+(D+1)y=2 ...(ii)⇒ -(D+1)x+y=0or (D+1)x-y=0 ...(x)From equation (ix) and (x), we have2x=1or x=1/2Now, substituting the value of x in equation (ix), we have D(1/2)+y=1or y=1-1/2=1/2Thus, the solution of the given system of differential equation is(x(t), y(t))=(e^(-t/2))[(-5/3)cos((sqrt(47)/2)t)-(125/3)sin((sqrt(47)/2)t)]+(20/3)cos(3t)+(20/3)sin(3t), (1/2)

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The students in a club are selling flowerpots to raise money.Each flowerpot sells for $15.

Part A

Write an expression that represents The total amount of money, in dollars, The students raise from selling flowerpots.
Answer your expression in the box provided. Enter only your expression.Please hurry!

Answers

Answer:

y = 15x

Step-by-step explanation:

For every flower pot purchased (y), the quantitity of the price (x) will go up by $15.

Answer:

y = 15x

Step-by-step explanation:

A cube with an edge of length s has a volume of 27 units.
What is the length of s?

Answers

Answer:

s = 3

Step-by-step explanation:

The volume formula for a cube is V = s^3, where “s” is the edge length. Since we know the volume and need to find “s,” we just do the inverse operation for an exponent, which is a radical. The cubed root of 27 is 3, so there’s your answer! Hope this is helpful & accurate. Best wishes.

Cost of a cell phone: $249.50
Markup: 30%

Answers

Answer:

$324.35

Step-by-step explanation:

249.50 x 1.30 = $324.35

please solve for x!!!

Answers

Answer:

x = 20

Step-by-step explanation:

The two angles are verticals angles and vertical angles are equal

7x -99 = 2x+1

Subtract 2x from each side

7x-99-2x =2x+1-2x

5x-99 =1

Add 99 to each side

5x-99+99 = 1+99

5x =100

Divide each side by 5

5x/5 =100/5

x = 20

Answer:

x=20

set them equal to eac hother

7x-99=2x+1

-2x+99-2x+99

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

5x=100

---- ------

5 5

x=20

Is 3. [3 marks] Use Gauss Divergence theorem to calculate S (5xi + ay 3 – 23 k).n dA over the sphere S: 1+ y + x2 = 9. splats J = ?? It-t? Lose - 2. [6 marks] Calculate the surface integral || G(r)da, where G = (1212 + 36)/2, the suru loob the parametrization r(u, v) = (3u, 2v, u), and 0 su 1, 0 Sv < 2.

Answers

1. Using Gauss Divergence theorem, we have to calculate S. (5xi + ay3 - 23k). ndA over the sphere S: 1+ y + x2 = 9. We have the following information: S.(5xi + ay3 - 23k).ndA over the sphere S: 1+ y + x2 = 9.

Gauss Divergence Theorem states that, The surface integral of a vector field F over a closed surface S equals the volume integral of the divergence of F over the enclosed volume V. To calculate the surface integral S.(5xi + ay3 - 23k).ndA, we need to first calculate the volume integral of the divergence of the vector field over the enclosed volume V which in this case is a sphere.

The divergence of the given vector field can be calculated as, div(F) = ∂P/∂x + ∂Q/∂y + ∂R/∂z = 5 + 3ay + 0 = 5 + 3ay

Thus, the volume integral of the divergence of F over the sphere S: 1+ y + x2 = 9 is given as ∭V div(F) dV = ∭V (5 + 3ay) dV.

The volume integral can be calculated using spherical coordinates.

We have the equation of the sphere as 1 + y + x2 = 9, substituting x = r sin θ cos φ, y = r sin θ sin φ, z = r cos θ, and simplifying, we get the limits of integration as 0 ≤ r ≤ 2, 0 ≤ θ ≤ π, and 0 ≤ φ ≤ 2π.

Therefore, the volume integral becomes:∭V div(F) dV = ∭V (5 + 3ay) dV = ∫0^2 ∫0^π ∫0^2π (5 + 3a(r cos θ sin φ)) r2 sin θ dr dθ dφ = 60πa

The surface integral of F over the sphere S can be calculated using the Gauss Divergence Theorem, which states that the surface integral of F over a closed surface S is equal to the volume integral of the divergence of F over the enclosed volume V.

Thus, S.(5xi + ay3 - 23k).ndA = ∭V div(F) dV = 60πa

Answer: S.(5xi + ay3 - 23k).ndA = 60πa2.

We are to calculate the surface integral ∬S G(r) da, where G = (12 + 12 + 36)/2 = 30.

The surface is given by r(u, v) = (3u, 2v, u), 0 ≤ u ≤ 1 and 0 ≤ v ≤ 2.

The surface area element da can be calculated as, da = |r/∂u x r/∂v| dudv = |(6, 0, 3) x (0, 2, 1)| dudv = |(-6, -3, 0)| dudv = 3 dudv

Hence, the surface integral ∬S G(r) da becomes ∬S G(r) da = ∫0^2 ∫0^1 G(r(u, v)) da = ∫0^2 ∫0^1 30 * 3 dudv = 180

Answer: ∬S G(r) da = 180

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PLSS HELPP D: WILL MARK BRAINLIEST :D

Answers

the 49 one because the square root is 7

Answer:

√49

Step-by-step explanation:

It's a perfect square root.

Please brainliest ;)

A box of macaroni & cheese says that it makes 25% more than a regular box. If a regular box makes 3 cups of macaroni & cheese, how many cups will this box make?

Thanks :)

Answers

Answer:

3.75

Step-by-step explanation:

25% = 0.25

3(0.25) = 0.75

3 + 0.75 = 3.75

Two very long, parallel wires are separated by d = 0.065 m. The first wire carries a current of I1 = 0.65 A. The second wire carries a current of I2 = 0.35 A.
1) Express the magnitude of the force between the wires per unit length, f, in terms of I1, I2, and d.
2)Calculate the numerical value of f in N/m.
3)Is the force repulsive or attractive?
4) Express the minimal work per unit length needed to separate the two wires from d to 2d.
5)Calculate the numerical value of w in J/m.

Answers

1. The work magnitude of the force between the wires per unit length, f, can be expressed using Ampere's Law:

f = μ₀ * I₁ * I₂ / (2πd)

2. The numerical value of f is 2 × 10⁻⁶ N/m.

3. Since the currents I₁ and I₂ are both positive, the force between the wires will be attractive.

4. The minimal work per unit length needed to separate the two wires from d to 2d can be calculated using the equation:

W = f * (2d - d) = f * d.

5. The numerical value of the minimal work per unit length needed to separate the two wires from d to 2d is 1.3 × 10⁻⁷ J/m.

What is Ampère's law?

Ampère's law, one of the fundamental correlations between electricity and magnetism, quantifies the relationship between an electric field's changing magnetic field and the electric current that creates it.

1. The work magnitude of the force between the wires per unit length, f, can be expressed using Ampere's Law:

f = μ₀ * I₁ * I₂ / (2πd),

where μ₀ is the permeability of free space, I₁ and I₂ are the currents in the wires, and d is the separation between the wires.

2. To calculate the numerical value of f in N/m, we need to substitute the given values into the formula:

μ₀ = 4π × 10⁻⁷ T·m/A (permeability of free space)

f = (4π × 10⁻⁷ T·m/A) * (0.65 A) * (0.35 A) / (2π * 0.065 m)

Simplifying:

f = 2 * 10⁻⁶ N/m

Therefore, the numerical value of f is 2 × 10⁻⁶ N/m.

3. The force between the wires is attractive when the currents flow in the same direction and repulsive when the currents flow in opposite directions. In this case, since the currents I₁ and I₂ are both positive, the force between the wires will be attractive.

4. The minimal work per unit length needed to separate the two wires from d to 2d can be calculated using the equation:

W = f * (2d - d) = f * d.

5. Substituting the value of f (2 × 10⁻⁶ N/m) and d (0.065 m) into the equation, we get:

W = (2 × 10⁻⁶ N/m) * (0.065 m)

Simplifying:

Work = 1.3 × 10⁻⁷ J/m

Therefore, the numerical value of the minimal work per unit length needed to separate the two wires from d to 2d is 1.3 × 10⁻⁷ J/m.

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Solve the following differential equation by using Laplace transform method. y" +2y' +y = cos2t where y(0)=1 y'(O)=1.

Answers

The solution to the given differential equation with the initial conditions y(0) = 1 and y'(0) = 1 is:

[tex]y(t) = -e^{-t}/10 + (11/10)t*e^{-t} + (1/10)cos(2t) + (3/10)sin(2t)[/tex]

To solve the given differential equation using Laplace transform, we will apply the Laplace transform to both sides of the equation and then solve for the transformed variable.

Let's denote the Laplace transform of y(t) as Y(s).

Taking the Laplace transform of both sides of the differential equation, we get:

[tex]s^2Y(s) + 2sY(s) + Y(s) = (s^2 + 2s + 1)/(s^2 + 4)[/tex]

Now, let's solve for Y(s):

[tex]Y(s)(s^2 + 2s + 1) = (s^2 + 2s + 1)/(s^2 + 4)\\Y(s) = (s^2 + 2s + 1)/(s^2 + 4)(s^2 + 2s + 1)[/tex]

Factoring the denominator:

[tex]Y(s) = (s^2 + 2s + 1)/((s + 1)^2(s^2 + 4))[/tex]

Now, we need to decompose the fraction into partial fractions. Let's express the numerator in terms of A, B, C, and D:

[tex]s^2 + 2s + 1 = A/(s + 1) + B/(s + 1)^2 + (Cs + D)/(s^2 + 4)[/tex]

To find the values of A, B, C, and D, we can equate the numerators:

[tex]s^2 + 2s + 1 = A(s + 1)(s^2 + 4) + B(s^2 + 4) + (Cs + D)(s + 1)^2[/tex]

Expanding and equating coefficients:

[tex]s^2 + 2s + 1 = A(s^3 + 5s^2 + 4s) + B(s^2 + 4) + (C(s^2 + 2s + 1) + D(s + 1)^2)[/tex]

Simplifying:

[tex]s^2 + 2s + 1 = (A + C)s^3 + (5A + C + D)s^2 + (4A + 2C + D)s + (4A + D)[/tex]

Equating coefficients:

A + C = 0 (coefficient of [tex]s^3[/tex])

5A + C + D = 1 (coefficient of [tex]s^2)[/tex]

4A + 2C + D = 2 (coefficient of s)

4A + D = 1 (constant term)

Solving these equations simultaneously, we find A = -1/10, B = 11/10, C = 1/10, and D = 3/10.

Now, substituting these values back into Y(s):

[tex]Y(s) = (-1/10)/(s + 1) + (11/10)/(s + 1)^2 + (1/10)(s + 3)/(s^2 + 4) + (3/10)/(s^2 + 4)[/tex]

To find y(t), we need to take the inverse Laplace transform of Y(s). Fortunately, we can use a Laplace transform table to find the inverse Laplace transform of each term.

The inverse Laplace transform of (-1/10)/(s + 1) is [tex]-e^{-t}/10.[/tex]

The inverse Laplace transform of (11/10)/(s + 1)² is (11/10)t*[tex]e^{-t}.[/tex]

The inverse Laplace transform of (1/10)(s + 3)/(s² + 4) is (1/10)cos(2t).

The inverse Laplace transform of (3/10)/(s² + 4) is (3/10)sin(2t).

Combining these results, the solution y(t) is:

[tex]y(t) = -e^{-t}/10 + (11/10)t*e^{-t} + (1/10)cos(2t) + (3/10)sin(2t)[/tex]

Therefore, the solution to the given differential equation with the initial conditions y(0) = 1 and y'(0) = 1 is:

[tex]y(t) = -e^{-t}/10 + (11/10)t*e^{-t} + (1/10)cos(2t) + (3/10)sin(2t)[/tex]

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Which expression is equivalent to

Answers

Answer:

Step-by-step explanation:

the first expression

The Taylor polynomial P, = (-10 * 9 about x = 0 is used to approximate the value of the function f at x=1 Find the value that verifies 5p (1)-(1)-500 n=1 n! Pa 1 384 1 384 0 ਤਕ OP PA 1 6144 PA 6144

Answers

The value that verifies 5p (1)-(1)-500 is -124.04

To approximate the value of the function f at x = 1 using the Taylor polynomial Pₙ = (-10)^n/ n! about x = 0, we need to find the value of P₅(1).

First, let's compute the derivatives of f(x) = e^x up to the fifth derivative:

f'(x) = e^x

f''(x) = e^x

f'''(x) = e^x

f''''(x) = e^x

f⁽⁵⁾(x) = e^x

Now, let's evaluate these derivatives at x = 0:

f(0) = e^0 = 1

f'(0) = e^0 = 1

f''(0) = e^0 = 1

f'''(0) = e^0 = 1

f''''(0) = e^0 = 1

f⁽⁵⁾(0) = e^0 = 1

Using these values, we can compute the Taylor polynomial P₅(x):

P₅(x) = f(0) + f'(0)(x - 0) + f''(0)(x - 0)²/2! + f'''(0)(x - 0)³/3! + f''''(0)(x - 0)⁴/4! + f⁽⁵⁾(0)(x - 0)⁵/5!

P₅(x) = 1 + 1x + 1x²/2! + 1x³/3! + 1x⁴/4! + 1x⁵/5!

Now, let's evaluate P₅(1):

P₅(1) = 1 + 1(1) + 1(1)²/2! + 1(1)³/3! + 1(1)⁴/4! + 1(1)⁵/5!

P₅(1) = 1 + 1 + 1/2 + 1/6 + 1/24 + 1/120

P₅(1) = 227/120

Therefore, the value that verifies 5P₅(1) - (1) - 500 is:

5P₅(1) - (1) - 500 = 5 * (227/120) - 1 - 500

= 1135/120 - 1 - 500

= 1135/120 - 120/120 - 60000/120

= (1135 - 120 - 60000)/120

= -59485/120

= -124.04

So, the value that verifies 5P₅(1) - (1) - 500 is approximately -124.04.

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[LOOK AT THE PICTURE URGENT]

Answers

Answer:B

Step-by-step explanation:if it's a negative 3/4x then in be there is a -4 and there is a -7 so we can do -7 -4 but 4 is a negative so it turns into a positive so it's _

-7+4 and it become a smaller negative so -7+4 = -3. So it has to be B. Hope this gets brainliest

AB
Round your answer to the nearest hundredth.
А
50°
6
12
B

Answers

Answer:

h = 7.832

Step-by-step explanation:

This is a right angled triangle so, taking 50 as reference angle,

hypotenuse = ?

perpendicular = 6

The ratio for p and h is given by

Sin 50 = p/h

Sin 50 = 6 /h

h = 6 / Sin 50

h = 7.832

If the coefficient of determination is 0.422, what percentage of the variation in the data
about the regression line is unexplained?
2 pts
42.2%
17.8%
82.2%
57.8%

Answers

The percentage of the variation in the data about the regression line that is unexplained is 100% - 42.2% = 57.8%. So, the correct option is D, 57.8%.

If the coefficient of determination is 0.422, the percentage of the variation in the data about the regression line that is unexplained is 57.8%. Coefficient of determination, denoted by R² is a statistical tool that measures how well the regression line approximates the real data points. It is also called the square of the correlation coefficient between the dependent and independent variables.

The coefficient of determination varies from 0 to 1, and it represents the proportion of the total variation in the dependent variable that is explained by the variation in the independent variable. A coefficient of determination of 0.422 indicates that the regression line explains only 42.2% of the total variation in the dependent variable. Hence, the percentage of the variation in the data about the regression line that is unexplained is 100% - 42.2% = 57.8%.

Therefore, the correct option is D, 57.8%.

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One angle measures 19° and another angle measures (4d − 9)°. If the angles are complementary, what is the value of d?

d = 7
d = 20
d = 25
d = 42.5

Answers

Answer:

d = 20

Step-by-step explanation:

90-19 = 71

(4d-9) = 71

4d = 80

d = 20

Answer:

d = 20

Step-by-step explanation:

Complementary angles are two angles that add up to 90°.

We know that one angle is 19° and the other is (4d − 9)°. So, we can set up the equation:

19 + (4d − 9) = 90.

Solving for d, we get:

19 + (4d − 9) = 90

19 + 4d − 9 = 90

4d + 10 = 90

4d = 80

d = 20

Therefore, the value of d is 20.

Are there outliers in the set of data below? Hint: Use your formulas from the lesson

52, 58, 62, 66, 67, 68, 68, 70, 70, 72, 73, 74, 76, 84, 90



Question 1 options:

52 and 90


68 and 70


There are no outliers

pls help

Answers

I think 68 and 70 is an outliers

Let M = {a E Ra > 1). Then M is a vector space under standard addition and scalar multiplication of real numbers. False True * Let W = {a + 2x + bx² € Pz: a, b E R} with the standard operations in P2. Which of the following statements is true? 1+xEW W is a subspace of P2. The above is true W is not a subspace of P.

Answers

The statement "W is a subspace of P2" is true because the set W, defined as W = {a + 2x + bx² ∈ P2: a, b ∈ R}, is a subspace of P2.

To determine if the set W = {a + 2x + bx² ∈ P2: a, b ∈ R} is a subspace of P2, we need to check if it satisfies three conditions: closure under addition, closure under scalar multiplication, and contains the zero vector.

Closure under addition: For any two polynomials p(x) = a + 2x + bx² and q(x) = c + 2x + dx² in W, their sum p(x) + q(x) = (a + c) + 4x + (b + d)x² is also a polynomial in W. This shows that W is closed under addition.

Closure under scalar multiplication: For any polynomial p(x) = a + 2x + bx² in W and any scalar c, the scalar multiple c * p(x) = ca + 2cx + cbx² is also a polynomial in W. Therefore, W is closed under scalar multiplication.

Contains the zero vector: The zero vector in P2 is the polynomial 0x² + 0x + 0, which can be expressed as a + 2x + bx² with a = 0 and b = 0. Since this polynomial satisfies the conditions of W, W contains the zero vector.

Since W satisfies all three conditions, it is a subspace of P2.

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NO LINKS!!!

A mechanic charges $45 to inspect your heater, plus $80 per hour to work on it. You owe the mechanic a total of $385. Write and solve an equation to find the amount of time (h) (in hours) the mechanic works on your heater.

What is the equation and and the answer?

Answers

Answer:

385=80x+45

x=4.25 hours

all I know is that it took him 4 hours and 32 minutes to work on it. 385-45=340/80=4.32

PLS HELP WITH WORKINGSSSSSSSS​

Answers

Answer:

60°

Step-by-step explanation:

90°-30°…

according to your question

Does anyone know a vb knowledge matters admin login?
I'm trying to complete the Sports & Entertainment Mogul

Answers

Answer:

Sadly no but also brainly isn't for this

Step-by-step explanation:

(Ima get so much hate rn from y'all)

Historical data indicated that the time students took to complete their CML quizzes could be modelled as a normal distribution with a variance of 123.7 minutes squared. A random sample of 37 students revealed a mean time of 439 minutes. Determine a 94% confidence interval for the average time students take to complete their CML quiz. State the lower bound of this interval (in minutes) to 2 decimal places

Answers

The 94% confidence interval for the average time students take to complete their CML quiz can be determined using the sample mean, sample size, and the given variance.

To calculate the confidence interval, we can use the formula:

Confidence Interval = sample mean ± (critical value) * (standard deviation / sqrt(sample size))

First, we need to find the standard deviation, which is the square root of the variance:

Standard Deviation = sqrt(123.7) = 11.11

Next, we find the critical value corresponding to a 94% confidence level. Since the sample size is large (n > 30), we can use the Z-distribution. For a 94% confidence level, the critical value is approximately 1.88.

Substituting the values into the formula:

Confidence Interval = 439 ± (1.88) * (11.11 / sqrt(37))

Calculating the confidence interval, we get:

Confidence Interval ≈ 439 ± 3.32

Therefore, the lower bound of the confidence interval is:

Lower bound ≈ 439 - 3.32 = 435.68 minutes (rounded to 2 decimal places).

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A stone is dropped from the upper observation deck of a tower, 900 m above the ground. (Assume g=9.8 m/s2.) (a) Find the distance (in meters) of the stone above ground level at time t, h(t)= (b) How long does it take the stone to reach the ground? (Round your answer to two decimal places.) (c) With what velocity does it strike the ground? (Round your answer to one decimal place.) m/s (d) If the stone is thrown downward with a speed of 3 m/s, how long does it take to reach the ground? (Round your answer to two decimal places.)

Answers

After considering the given data we conclude that the distance between stone and ground level [tex]h(t) = -4.9t^2 + 900[/tex], time taken for the stone to reach the ground 18.22 seconds,the velocity with which it strikes the ground 178.76 m/s, if thrown with a down ward speed of 3m/s then the duration needed is 18.47 seconds.

A stone is dropped from the upper observation deck of a tower, 900 m above the ground. We can use the kinematic equations of motion to answer the following questions:
a) The distance of the stone above ground level at time t can be found using the equation:
[tex]h(t) = -1/2gt^2 + v_0t + h_0[/tex]
where g is the acceleration due to gravity (9.8 m/s²), v0 is the initial velocity (0 m/s), h0 is the initial height (900 m), and t is the time elapsed. Plugging in the values, we get:
[tex]h(t) = -4.9t^2 + 900[/tex]
b) To find how long it takes for the stone to reach the ground, we need to find the time when h(t) = 0:
[tex]-4.9t^2 + 900 = 0[/tex]
Solving for t, we get:
[tex]t = \sqrt(900/4.9) = 18.22 seconds[/tex]
Therefore, it takes the stone 18.22 seconds to reach the ground.
c) To find the velocity with which the stone strikes the ground, we can use the equation:
[tex]v(t) = -gt + v_0[/tex]
where v(t) is the velocity at time t. Plugging in the values, we get:
[tex]v(t) = -9.8(18.22) + 0 = -178.76 m/s[/tex]
Therefore, the stone strikes the ground with a velocity of 178.76 m/s.
d) If the stone is thrown downward with a speed of 3 m/s, we can use the same equation [tex]v(t) = -9.8(18.22) + 0 = -178.76 m/s[/tex] to find how long it takes to reach the ground. This time, [tex]v_0[/tex] is -3 m/s (since it is thrown downward) and [tex]h_0[/tex] is still 900 m. Plugging in the values, we get:
[tex]-4.9t^2 - 3t + 900 = 0[/tex]
Solving for t, we get:
t = 18.47 seconds
Therefore, it takes the stone 18.47 seconds to reach the ground when thrown downward with a speed of 3 m/s.
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find a rational number between 3/5 and 4/5 ( see I just only want one so please don't give me all five)
give me the process too
Thanks ​

Answers

Answer:

[tex]\dfrac{7}{10}[/tex]

Step-by-step explanation:

We need to find a rational number between 3/5 and 4/5.

We can find a rational number between two fractions as :

[tex]\dfrac{a+b}{2}[/tex]

We have, a = 3/5 and b = 4/5

So,

[tex]\dfrac{\dfrac{3}{5}+\dfrac{4}{5}}{2}\\\\=\dfrac{\dfrac{7}{5}}{2}\\\\=\dfrac{7}{10}[/tex]

So, a rational number between 3/5 and 4/5 is equal to 7/10.

Suppose sales of shoe companies follow normal distribution with unknown population mean and a known population standard deviation of 3. It is suspected that on an average the revenue of the shoe companies is $8 million. A random sample of 400 companies was taken and the sample average was found to be $8.30 million. We want to determine whether the average revenue is significantly different than $8 million. The critical value (upper) is_____________ therefore we can __________the Null at the 1% level of significance

2.33, reject
2.57, not reject
1.96, not reject
2.57, reject

Answers

The critical value (upper) for a 1% level of significance is 2.33. Therefore, we can reject the null hypothesis.

To determine whether the average revenue is significantly different from $8 million, we perform a hypothesis test using the sample data. The null hypothesis (H0) states that the average revenue is equal to $8 million, while the alternative hypothesis (Ha) states that the average revenue is significantly different.

Given a sample of 400 companies, the sample average revenue is found to be $8.30 million, and the population standard deviation is known to be 3. We can use a z-test since the population standard deviation is known and the sample size is large.

Next, we calculate the test statistic (z-score) using the formula: z = (sample mean - hypothesized mean) / (population standard deviation / √sample size).

Plugging in the values, we get z = (8.30 - 8) / (3 / √400) = 1.73.

To determine the critical value (upper) at a 1% level of significance, we look up the z-value from the standard normal distribution table, which is approximately 2.33.

Since the calculated z-score of 1.73 is less than the critical value of 2.33, we do not have enough evidence to reject the null hypothesis. Therefore, we cannot conclude that the average revenue is significantly different from $8 million at a 1% level of significance.

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pls help im pretty sure its easy i just forgot

Answers

the average can be calculated by adding the scores together and then dividing by the number of scores.

we can set up an equation:

let x = test score needed on next test

(72+72+80+x)/4 = 71

multiply both sides by 4

72+72+80+x = 284

add like terms

224+x=284

subtract 224 from both sides

x=60

she will need a 60 for her average to be 71

She needs to score a 60 to have a average score of 71,

72+72+80+60=284

284/4=71

Ariana orders 4 large pizzas and 1 order of breadsticks The total for her order is $34.46. Emily orders 2 large pizzas and 1 order of breadsticks. $18.48 is the total for her order. Determine the order for 1 large pizza and 1 order of breadsticks?

Answers

4p + 1b = 34.46
2p + 1b = 18.48

Solve either equation for b

2p + b = 18.48
b = 18.48 - 2p

Substitute into first equation
4p + 18.48 - 2p = 34.46
2p + 18.48 = 34.46
2p = 15.98
p = $7.99

Plug back into either equation to find cost of breadsticks

2(7.99) + b = 18.48
15.98 + b = 18.48
b = $2.50

One pizza + breadstick
$7.99 + $2.50
$10.49 :)

Determine Px H=34, o=12, n=35 ox (Round to three decimal places F and a from the given parameters of the population and sample size. 11 Determine and o from the given parameters of the population and sample size. u-34, a 12, n=35 K- (Round to three decimal places as needed).

Answers

The value of μₓ is 77 and σₓ is 3 when [tex]\mu[/tex] = 77, [tex]\sigma[/tex] = 21, and n = 49.

We have

[tex]\mu[/tex] = 77,

[tex]\sigma[/tex] = 21,

and Sample size, n = 49.

The formula to determine the sample mean (μₓ) is

=μx

= μ

=77

Similarly, σₓ= σ/(√(n))

Therefore, we substitute the given values,

σx = 21/(√(49))

σx= 3

The standard deviation is a statistical metric used to quantify the extent of variation or dispersion within a dataset. It gauges the degree to which values deviate from the average (mean) value.

A larger standard deviation suggests a greater degree of variability, while a smaller standard deviation suggests less variability.

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I WILL GIVE BRAINLIEST!!!

consider the polynomial function q(x)=-2x^8+5x^6-3x^5+50

end behavior

Answers

Answer:

Use the degree and the leading coefficient to determine the behavior.

Falls to the left and falls to the right

Step-by-step explanation:

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