An educational researcher devised a wooden toy assembly project to test learning in 6-year-olds. The time in seconds to assemble the project was noted, and the toy was disassembled out of the child's sight. Then the child was given the task to repeat. The researcher would conclude that learning occurred if the mean of the second assembly times was less than the mean of the first assembly times.
Find the 99% confidence interval for the difference in means.
Child
2
3
4
Trial 1
108 140
154
115
Trial 2
99
118 154
96
5
130
108
107
102
110
0 0.7 0-07<4-4 < 23.5
0-29 O 29

To determine what percentage of working adults in your neighborhood regularly ride the bus to work, the best sampling method and survey question are D. Enter the names of all adults in your neighborhood into a computer program to randomly select a sample and ask, "Do you ever ride the bus to work?"

The best sampling method involves random sampling of the population.

A random sample gives each member of the population an equal chance of being selected as a participant in the survey.

It is also described as a probability sampling method.

Thus, in this instance, the correct option is D.

Learn more about sampling methods at https://brainly.com/question/28292794.

#SPJ1

The lateral surface area of the cylinder is approximately 175.84 square meters.

We have,

The lateral surface area of a cylinder.

= 2πrh

where r is the radius of the base, h is the height of the cylinder, and π is approximately 3.14.

Now,

r = 2 m, h = 14 m

Substituting these values in the formula, we get:

Lateral surface area = 2πrh

= 2 x 3.14 x 2 x 14

= 175.84 m² (rounded to the nearest tenth)

Therefore,

The lateral surface area of the cylinder is approximately 175.84 square meters.

Learn more about cylinder here:

https://brainly.com/question/15891031

#SPJ1

-63.63 m/s is the rate of change of the distance between the plane and the car when both are maximum speed and the plane is ahead by 70m?

Let's use the Pythagorean theorem to relate the distance between the car and the plane to their individual distances traveled. Let d be the distance traveled by the car, then the distance traveled by the plane is d + 70 (since the plane is ahead by 70m). Then, the distance between them is given by:

distance = [tex]\sqrt{d^{2}+500^{2} }[/tex] (using Pythagorean theorem)

Now, let's differentiate both sides with respect to time (t) to find the rate of change of the distance between the car and the plane:

d(distance)/dt = (1/2)[tex](d^{2} +500^{2} )^{(-1/2)}[/tex] * (2d/dd)(dd/dt)

where the first term on the right side is the derivative of the square root expression and the second term is the derivative of d with respect to time.

Now we need to find d in terms of t, given the maximum speeds of the car and the plane. Let's assume that they both start at time t = 0 and are racing for a time of T. Then, we can write:

d = 200T (distance traveled by the car)

d + 70 = 300T (distance traveled by the plane)

Solving for T, we get:

T = 70/100 = 0.7 hours = 42 minutes

Substituting T back into the expressions for d, we get:

d = 200(0.7) = 140 km

d + 70 = 300(0.7) = 210 km

Now we can substitute these values into the expression for the rate of change of the distance between the car and the plane:

d(distance)/dt = (1/2)[tex](d^{2} +500^{2} )^{(-1/2)}[/tex]  * (2d/dd)(dd/dt)

d(distance)/dt = (1/2)[tex](140^{2} +500^{2} )^{(-1/2)}[/tex] * (2*140/60)(300 - 200)

d(distance)/dt = -63.63 m/s

Therefore, the rate of change of the distance between the car and the plane when both are at maximum speed and the plane is ahead by 70m is approximately -63.63 m/s. Note that the negative sign indicates that the distance between them is decreasing, since the plane is ahead of the car.

To learn more about distance here:

https://brainly.com/question/15172156

#SPJ1

Answer:

The answer to your problem is, 7

Step-by-step explanation:

First you can either convert;

ml to liter

liter to ml

I will use liter to ml.

1.75 liters in ml is 1750 ml

So we can then divide, 1750 / 250 = 7

Which is the answer

Thus the answer to your problem is, 7

Answer:

  3/23 or 0.1304 or 13%

Step-by-step explanation:

Given 3 students have a brother and sister, and 20 students have only a brother, you want the probability that a student who has a brother also has a sister.

The conditional probability formula is ...

  P(A | B) = P(A&B)/P(B)

Here, this means ...

  P(has a sister | has a brother) = P(has both)/P(has a brother)

  = 3/(3 +20)

  = 3/23 ≈ 0.1304 ≈ 13% . . . . . probability of a sister if has a brother

<95141404393>

The values of c that satisfy Rolle's Theorem is 2.15 or -0.15.

The value of c that satisfies Roll's theorem is calculated as follows;

y = x³ - 3x² - x; [-1, 3]

Based on Roll's theorem conditions, since the function is a polynomial it is continuous.

The derivative is also a polynomial.

y' = 3x² - 6x - 1

The final condition;

y(-1) = (-1)³ - 3(-1)² - (-1)

y(-1) = -1 - 3 + 1

y(-1) = -3

y(3) = (3)³ - 3(3)² - 3

y(3) = 27 - 27 - 3

y(3) = -3

The three conditions of Rolle's theorem is statisfied,  so there exists at least one value of c in the interval (-1, 3) such that y'(c) = 0.

y' = 3x² - 6x - 1

y'(c) = 3c² - 6c - 1

3c² - 6c - 1 = 0

Solve the quadratic equation using formula method;

a = 3, b = -6, c = -1

c = 2.15 or - 0.15

Learn more about Rolle's theorem here: https://brainly.com/question/29438393

#SPJ1

Step-by-step explanation:

a) 11*5=55

15*5=75

8*5+5=45

b) No, because (55+75+45=175°) and the perimeter of a triangle is 180°

Answer:

2(5(11) + 5(2.5) + 11(2.5))

= 2(55 + 12.5 + 27.5) = 2(55 + 40) = 2(95)

= 190 square centimeters

The surface area of the larger pyramid in discuss would be 25 times the surface area of the smaller pyramid.

It follows from the task content that the surface area of the larger pyramid and the smaller pyramid are to be compared.

By observation; the differing dimensions are such that the ratio of the larger pyramid to the smaller pyramid is; 10 / 2 = 5.

On this note, the ratio of the area of the pyramids are such that the larger pyramid is 5² = 25 times larger than that of the smaller pyramid.

Read more on square pyramids;

https://brainly.com/question/27821917

#SPJ1

Answer: the answer is E

Step-by-step explanation:

Remember that the coordinates (5,−2π3) tell us the radius r=5 and the angle θ=−2π3. So the point should be on the circle labeled 5 and form an angle of −2π3 with the positive x-axis. Point E is the correct point.

Answer:

Step-by-step explanation:

Remember that the coordinates (5,−2π/3) tell us the radius r=5 and the angle θ=−2π/3. So the point should be on the circle labeled 5 and form an angle of −2π/3 with the positive x-axis. Point E is the correct point.

Answer:

Me: 60

Zayn and Attia: 6

Step-by-step explanation:

12 = 2 × 2 × 3

20 = 2 × 2 × 5

LCM of 12 and 20 = 2 × 2 × 3 × 5 = 60

My number is 60.

Zayn's and Attia's numbers are 6.

The measure of angle C is given as follows:

m < C = 44º.

To obtain the measures of the angles in this problem, we must consider that the sum of the measures of the internal angles of a triangle is of 180º.

Considering that the sum of the measures of the internal angles of a triangle is of 180º, and angles C, D and E, the value of x is obtained as follows:

4x - 16 + 6x - 1 + 4x - 13 = 180

14x - 30 = 180

14x = 210

x = 210/14

x = 15.

Hence the measure of angle C is obtained as follows:

m < C = 4 x 15 - 16 = 44º.

More can be learned about angle measures at https://brainly.com/question/25716982

#SPJ1

The values of the variables x and y are;

1, x = -y and y = 5. Option D

2. x= 1 and y = -1. Option A

Using the substitution method of solving simultaneous equations, we have;

4x + 7y = 19

y - x = 9

Now, make 'y' the subject from equation 2

y = 9 + x

Substitute the equation into equation 1

4x + 7(9 + x)= 19

expand the bracket, we have;

4x + 63 + 7x = 19

collect the like terms

11x = -44

x = -4

then,

y = 9 - 4 = 5

-3x + y = -4

4x + 3y = 1

make y' the subject from equation 1

y =-4 + 3x

Substitute the value

4x + 3(-4 + 3x) = 1

expand the bracket

4x - 12 + 9x = 1

13x = 13

x = 1

Substitute the value

y = -4 + 3

y = -1

Learn about simultaneous equations at: https://brainly.com/question/16863577

#SPJ1

The next number in the series would be 31 so the complete series is 101, 001, 66, 31.

The first thing we observe is that 101 equals 100 plus one. The second term, 001, equals 0 plus 1. Now consider the distinctions between consecutive terms:

101 - 001 = 100

001 - 66 = -65

When we look at the disparities (100, -65), we can see a pattern. The difference between 100 and 65 is a factor of 35. We can now apply this distinction to the final term in the series:

66 - 35 = 31

So the next number in the series is 31, completing the sequence: 101, 001, 66, 31.

Find out more on series at https://brainly.com/question/26148523

#SPJ1

The value of y for this ordered pair is 7.

In Mathematics and Geometry, the point-slope form of a straight line can be calculated by using the following mathematical equation (formula):

y - y₁ = m(x - x₁)

Where:

First of all, we would determine the slope of line AC;

Slope (m) = (y₂ - y₁)/(x₂ - x₁)

Slope (m) = (-2 + 8)/(-4 + 8)

Slope (m) = 6/4

Slope (m) = 3/2

At data point (-4, -2) and a slope of 3/2, a linear equation for this line can be calculated by using the point-slope form as follows:

y - y₁ = m(x - x₁)

y + 2 = 3/2(x + 4)  

y = 3x/2 + 4

When x = 2, the y-value is given by;

y = 3(2)/2 + 4

y = 7.

Read more on point-slope here: brainly.com/question/24907633

#SPJ1

The solution to the equation is x = 10 or x = -2.

An equation refers to a mathematical expression showing that two expressions are equal.

It must have variables (e.g. a, c, x, y), constants (like 1, 13, 50, etc), and mathematical operations (like +, -, *, /).

To solve for x, we shall start with the given equation:

x + 6 = √(2x + 29) + 9

Subtract 9 from both sides:

x - 3 = √(2x + 29)

Square both sides:

[tex](x - 3)^2[/tex] = 2x + 29

Expand the left side:

[tex]x^2[/tex] - 6x + 9 = 2x + 29

We then subtract 2x and 9 from both sides:

[tex]x^2[/tex] - 8x - 20 = 0

Next, actor the quadratic equation:

(x - 10)(x + 2) = 0

Therefore, the equation x = 10 or x = -2

Learn more about equation at brainly.com/question/29174899

#SPJ1

Answer:

16

Step-by-step explanation:

2×2×2×2=16

So, the answer is 16.

The solution in the equation is x = 12.

We have,

To solve the logarithmic equation log (x − 2) = 1,

We can use the definition of logarithm which states that log base b of x equals y if and only if b to the power of y equals x, where b is the base of the logarithm.

In this case, the base is not specified, so we assume it is 10, which is the common base used in most calculators and mathematical applications

Using the exponential form, we have:

log (x - 2) = 1

10^1 = x - 2

10 = x - 2

x = 12

Therefore,

The solution is x = 12.

Learn more about solutions of equations here:

https://brainly.com/question/545403

#SPJ1

Answer:

The union of sets A and B is:

A U B = {1, 2, 3, 4, 6, 8}

Answer:

p≥35

Step-by-step explanation:

because you have done 15 so you subtract 15 from 50 giving you 35 and then you would say p is greater than or equal to 35 cause 50 pages is your minimum

The length of the secant line JK is 32.

The secant-tangent power theorem states that if a tangent and a secant are drawn from a common external point to a circle, then the product of the length of the secant segment and its external part is equal to the square of the length of the tangent segment.

It is expressed as:

( tangent segment )² = External part of the secant segment × Secant segment.

From the diagram:

Tangent line JI = 24

External part of the secant segment LJ = 18

Secant segment JK = x + 18

Plug these values into the above formula and solve for b.

( tangent segment )² = External part of the secant segment × Secant segment.

24² = 18 × ( x + 18 )

576 = 18x + 324

18x = 576 - 324

18x = 252

x = 252/18

x = 14

Hence, secant line JK will be:

x + 18 = 14 + 18 = 32

Learn more about secant tangent power theorem here: brainly.com/question/26407978

#SPJ1

Answer:

Concave up on the intervals (-π/2, π/2), and concave down on the intervals (-π,-π/2) and (π/2,π).

Step-by-step explanation:

To find the intervals where the function y = -cot(x) is concave up and concave down, we need to find the second derivative of the function and then determine its sign for different intervals.

First, we find the first derivative of y = -cot(x):

dy/dx = csc^2(x)

Then, we find the second derivative by differentiating the first derivative:

d^2y/dx^2 = -2csc^2(x) * cot(x)

We know that the function is concave up when the second derivative is positive, and concave down when the second derivative is negative.

Now, we need to determine the intervals where the second derivative is positive and negative.

d^2y/dx^2 > 0 when:

-2csc^2(x) * cot(x) > 0

csc^2(x) < 0 and cot(x) < 0 or csc^2(x) > 0 and cot(x) > 0

Since csc^2(x) is always positive, we can ignore the first inequality. Therefore, the second derivative is positive when cot(x) > 0.

d^2y/dx^2 < 0 when:

-2csc^2(x) * cot(x) < 0

csc^2(x) > 0 and cot(x) < 0 or csc^2(x) < 0 and cot(x) > 0

Since csc^2(x) is always positive, we can ignore the first inequality. Therefore, the second derivative is negative when cot(x) < 0.

Recall that cot(x) = cos(x)/sin(x), which changes signs at x = kπ, where k is an integer.

So, we can now use this information to determine the intervals of concavity:

   For x in (-π/2,0) and (0,π/2), cot(x) is positive and therefore, the function is concave up.

   For x in (-π,-π/2) and (π/2,π), cot(x) is negative and therefore, the function is concave down.

Therefore, the function y = -cot(x) is concave up on the intervals (-π/2, π/2), and concave down on the intervals (-π,-π/2) and (π/2,π).

Answer: r=2sinθ.

Step-by-step explanation:To convert to polar coordinates, we use the relationships

xy=rcosθ=rsinθ.

Substituting these into the given equation, we find

x2+y2(rcosθ)2+(rsinθ)2r2cos2θ+r2sin2θ=2y=2(rsinθ)=2rsinθ

Factoring and applying the Pythagorean identity, we obtain

r2(cos2θ+sin2θ)r2(1)r2=2rsinθ=2rsinθ=2rsinθ

Dividing both sides by r yields

r2rr=2rsinθr=2sinθ

Thus, a polar equation representing the given function is r=2sinθ.

Answer:

16

Step-by-step explanation:

24 divided by X(3) is equal to 8, then 8+8 equals 16 (EASY)

After two years, Swathu will pay back the debt in full, which comes to Rs. 105287.27.

To find the total amount Swathu will pay back after 2 years on a loan of Rs. 90,000 with an interest rate of 8% per annum compounded half-yearly, we can use the formula for compound interest:

[tex]A = P(1 + r/n)^{nt[/tex]

where:

A = the total amount Swathu will pay back

P = the principal amount borrowed (Rs. 90,000)

r = the annual interest rate (8%)

n = the number of times the interest is compounded per year (2 times, since it is compounded half-yearly)

t = the time period (2 years)

Substituting these values into the formula, we get:

[tex]A = 90,000(1 + 0.08/2)^{2*2}\\\\A = 90,000(1 + 0.04)^4\\\\A = 90,000(1.04)^4\\\\A = 90,000(1.16985856)\\[/tex]

A = 105287.27 (rounded to the nearest tenth)

Therefore, Swathu will pay back a total of Rs. 105287.27 after 2 years on the loan.

Learn more about compound interest here:

https://brainly.com/question/29335425

#SPJ1