The difference between an observational study and an experiment is thatin an observational study, only one group is studied, and in an experiment, two groups are studied.in an observational study, the researchers do not control treatment, and in an experiment, they do.in an experiment, cause-and-effect is analyzed, and in an observational study, it is not.in an experiment, one group is studied over a short period of time, and in an observational study, the group is studied over a longer period of time.

The sound emitted from the jet plane has a sound intensity of approximately 149.13 decibels.

Using the formula:

D = 10 * log(I/I0),

where D represents the sound intensity in decibels, I is the given sound intensity, and I0 is the reference intensity of 10^-12 watts per square meter.

Substituting the given values:

D = 10 * log(8.2*10^2 / 10^-12).

To simplify the calculation, we can rewrite the division as multiplication by the reciprocal:

D = 10 * log(8.2*10^2 * 10^12).

Using the logarithm property log(a * b) = log(a) + log(b):

D = 10 * (log(8.2) + log(10^2) + log(10^12)).

Using the logarithm property log(a^b) = b * log(a):

D = 10 * (log(8.2) + 2 * log(10) + 12 * log(10)).

Since log(10) = 1:

D = 10 * (log(8.2) + 2 + 12).

D = 10 * (log(8.2) + 14).

Using a calculator or logarithm table, we can find log(8.2) ≈ 0.913.

D = 10 * (0.913 + 14).

D = 10 * 14.913.

D ≈ 149.13.

Therefore, the sound emitted from the jet plane has a sound intensity of approximately 149.13 decibels.

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The correct option is b, the pair of consecutive interior angles is 1 and 7.

First, we can see that the interior angles are the angles that are "interior" to the intersections.

These are 1, 4, 6, and 7.

Because the two lines are parallel, the consecutive interior angles are angles that would be adjacent (add up to 180°) but that are in different intersections.

Then the consecutive interior angles are:

3 and 6

1 and 7

The correct option is b.

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Here are two significant advantages of a 401(k) over an IRA:

Higher Contribution Limits: 401(k) plans allow for higher annual contributions compared to IRAs. The contribution limit for a 401(k) is $19,500 (or $26,000 for individuals aged 50 and older), while the limit for an IRA is $6,000 (or $7,000 for individuals aged 50 and older).

Employer Contributions and Matching: 401(k) plans often offer employer contributions and matching programs. Employers may contribute to an employee's 401(k) account, adding to their retirement savings without any direct cost to the employee.

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Answer:

The answer is D, the last one.

Answer: D = 100π square units

Step-by-step explanation:

The formula to calculate the circumference of a circle is C = 2πr, where C is the circumference and r is the radius of the circle.

In this case, we have a circumference of 20π units, so we can set up the equation as follows:

20π = 2πr

To find the radius, we can divide both sides of the equation by 2π:

r = (20π) / (2π)

Simplifying further:

r = 10

Now that we have the radius, we can calculate the area of the circle using the formula A = πr^2:

A = π * (10)^2

A = π * 100

A = 100π

The statements that are true regarding the expression with the exponents -1, -3, and 1 are;

An exponent is a quantity or power to which a value, expression or number is to be raised.

The specified expression can be presented as follows;

8⁻¹ × 8⁻³ × 8

Therefore; 8⁻¹ × 8⁻³ × 8 = 8⁽⁻¹ ⁺ ⁻³ ⁺ ¹⁾ = 8⁻³ = 1/8³

1/8³ = 1/512

Similarly, we get; 8⁷ × 8⁻¹⁰ = 8⁽⁷ ⁻ ¹⁰⁾ = 8⁻³ = 1/8³

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The measures of angle T and angle V are T = 90 and V = 90

From the question, we have the following parameters that can be used in our computation:

The circle

The point T and V are at the tangent of the circle

By definition, the tangent is perpendicular to the radius of the circle, with which it intersects.

This means that the angle T and angle V are right angled

Using the above as a guide, we have the following:

T = 90 and V = 90

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The value of x is 9

To find the value of x for which the rational expression is equal to zero, we need to set the numerator equal to zero:

x - 9 = 0

Solving for x:

x = 9

Therefore, the value of x = 9.

Looking at the denominator (x - 4)(x + 4), we see that it contains two factors: (x - 4) and (x + 4). For the entire expression to equal zero, either the numerator or one of the factors in the denominator must equal zero.

Setting each factor in the denominator equal to zero:

x - 4 = 0 or x + 4 = 0

x = 4 or x = -4

These are the valid values of x for which the rational expression is equal to zero.

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The points that represent this data set are shown in the scatter plot attached below.

In this exercise, we would plot the number sold on the x-coordinates of a scatter plot while the prices ($) would be plotted on the y-coordinate of the scatter plot through the use of Microsoft Excel.

On the Microsoft Excel worksheet, you should right click on any data point on the scatter plot, select format trend line, and then tick the box to display a linear equation for the line of best fit on the scatter plot.

Based on the scatter plot shown below, which models the relationship between the number sold and the prices ($), a linear equation for the line of best fit is as follows:

y = 0.23x + 1.00

In conclusion, the slope of the line is 0.23 and the y-intercept is 1.00.

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Answer:

  x = 2

Step-by-step explanation:

You want the value of x that satisfies x|x| = 4.

The absolute value function splits the domain of the equation into two parts.

For x < 0, the equation is ...

  x(-x) = 4

  x² = -4

There are no real solutions in this domain.

For x ≥ 0, the equation is ...

  x² = 4

  x = √4 = 2

The only solution is x = 2.

__

Additional comment

In the attachment, we have rewritten the equation to ...

  x|x| -4 = 0

The graphing calculator readily identifies x-intercepts, so this is a convenient way to find the solution. You will notice that for x < 0, the graph is of -x²-4, which is never zero.

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The lateral surface area of the triangular base prism is 288 m².

The lateral area of the triangular base prism can be found as follows:

Lateral area of the triangular base prism = (a + b + c)h

where

Therefore,

a = 7 m

b = 8 m

c = 9 m

h = 12 m

Therefore,

Lateral area of the triangular base prism = (7 + 8 + 9)12

Lateral area of the triangular base prism = 24 × 12

Lateral area of the triangular base prism = 288 m²

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Answer:

16.829 minutes

Step-by-step explanation:

To solve this problem, we need to set up a system of equations based on the given information. Let's define the variables:

Let x be the number of minutes.

Let y be the price in cents.

For calling card A, the price can be calculated using the formula: y = 69 + 1.9x

For calling card B, the price can be calculated using the formula: y = 6x

We want to find the number of minutes (x) where the price (y) is the same for both cards. To set up the system of equations, we equate the two expressions for y:

69 + 1.9x = 6x

Now, we can solve this equation to find the value of x, which represents the number of minutes where the prices are equal.

69 + 1.9x = 6x

To simplify the equation, we can subtract 1.9x from both sides:

69 = 6x - 1.9x

Combining like terms, we have:

69 = 4.1x

To isolate x, we divide both sides of the equation by 4.1:

69 / 4.1 = x

Simplifying the division gives us:

16.829 = x

Therefore, the number of minutes (x) where the price (y) is the same for both calling cards A and B is approximately 16.829 minutes.

Hope this helps!

Answer:

For calling card A: y = 0.019x + 0.69

For calling card B: y = 0.06x

Step-by-step explanation:

For calling card A: y = 0.019x + 0.69

For calling card B: y = 0.06x

Set the prices equal to each other to find when they are the same:

0.019x + 0.69 = 0.06x

Simplify and solve for x:

0.041x = 0.69

x = 16.83 (rounded to two decimal places)

Therefore, if a person expects to talk for 16.83 minutes or more, calling card A will be cheaper. If they expect to talk for less than 16.83 minutes, calling card B will be cheaper.

Answer:

m<A = 66.2°

Step-by-step explanation:

m<A + m<B = 180°

m<B = 113.8°

m<A + 113.8° = 180°

m<A = 180° - 113.8°

m<A = 66.2°

Answer: 17 months

Step-by-step explanation:

Total cost of the bike = $1,867

Down payment = $320

so $1,867 - $320 = $1,547

$91 * 17 = 1,547

(17 = months) so $91 * 17 months = 1,547

Answer:

∫(1 - 25x²) dx

Step-by-step explanation:

Answer:

The figure is omitted--please sketch it to confirm my answer.

[tex]\pi {(5 \sqrt{2}) }^{2} - {10}^{2} [/tex]

[tex]50\pi - 100 = 50(\pi - 2) = 57.08[/tex]

The area inside the square and outside the circle is about 57.08 cm^2.

The correct option is the second one, the order is:

g(x), f(x), h(x).

To find the rate of change for a function f(x) on an interval [a, b] we need to get:

R = (f(b) - f(a))/(b - a)

Here the interval is [-1, 3]

The first function is:

f(x)=  (x + 3)² - 2

Evaluating we get:

f(-1) = (-1 + 3)² - 2

f(-1) = 2² - 2 = 4 -2 = 2

and f(3) = (3 + 3)² - 2 = 34

Then the rate is:

R = (34 - 2)/(3 + 1) = 8

For g(x) we can use the graph, we have:

R = (0 + 2)/4 = 1/2

For the last function we need to use the table, then we will get:

R = (62 - 14)/(3 + 1) = 12

Then the order, from least to greatest is:

g(x), f(x), h(x).

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Answer:

The sum of 33, 78, 10, 98, and 76 is 295.

Answer:

295

Step-by-step explanation:

add the numbers by using the addiction sign

(a) Using Excel, the calculations are shown below:

Mean = 608.67

Median = 610.00

Mode = 610.00

Standard Deviation =  96.89

(b) The measure of central tendency would be appropriate are  the median and the mode.

The median is fitting  because it  is a representation of the middle value in the data set and is not affected by extreme values.

We can see that our  median rent is $610.00 and an appropriate representation of the typical rent paid by the students.

The mode is $610.00 and also an indication that this rent amount is the most common among the students.

In conclusion, a  measure of the variability or dispersion in the data set is provided by the standard deviation, which is determined to be 96.89. It demonstrates how widely the rents vary from the mean.

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The derivative of function f(w) = [tex]2/(w^2 - 4)^5 ~is ~f'(w) = -40~w~(w^2 - 4)^{-6}.[/tex]

We have,

To find the derivative of the function [tex]f(w) = 2/(w^2 - 4)^5[/tex], we can use the chain rule and the power rule for differentiation.

Let's go through the steps:

First, rewrite the function as [tex]f(w) = 2(w^2 - 4)^{-5}.[/tex]

Now, let's differentiate f(w) with respect to w:

[tex]f'(w) = d/dw~ [2(w^2 - 4)^{-5}][/tex]

To apply the chain rule, we need to differentiate the outer function and multiply it by the derivative of the inner function.

Using the power rule, the derivative of (w² - 4) with respect to w is 2w.

Applying the chain rule:

[tex]f'(w) = -10 \times 2(w^2 - 4)^{-6} \times 2w[/tex]

Simplifying further:

[tex]f'(w) = -40w(w^2 - 4)^{-6}[/tex]

Therefore,

The derivative of function f(w) = [tex]2/(w^2 - 4)^5 ~is ~f'(w) = -40~w~(w^2 - 4)^{-6}.[/tex]

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Answer:

They would stop jumping rope at 12:46

Step-by-step explanation:

I'd probably say P.M considering the fact that I don't think kids would be having recess at midnight

Answer:  A  129

Step-by-step explanation:

Because the 2 chords are the same (lines in the circle), the 2 arcs are the same  create an equation that makes them equal

3x+24 = 4x -11             >bring x to one side by subtracting both sides by 3x

24 = x -11                     > add both sides by 11

35 = x

Now that we have solved for x you need to plug that back into the equation for BC

BC= 4x-11

BC = 4(35) - 11

BC =  140 - 11

BC = 129                   >A

Answer:

To find out how many megabytes have been downloaded, we can multiply 287 by 0.144 (which represents 14.4% as a decimal).

The calculation is:

287 x 0.144 = 41.328

Rounded to the nearest tenth, the number of megabytes downloaded is 41.3.

The value of x that makes [tex]5^x = 625[/tex] true is x = 4.

To determine the value of x in the equation [tex]5^x = 625[/tex], we need to find the exponent that results in 625 when applied to the base 5.

Since 625 can be expressed as 5 raised to the power of 4 ([tex]5^4 = 625[/tex]), the value of x that satisfies the equation is 4.

When we substitute x = 4 into the equation, we get [tex]5^4 = 625[/tex], which is true.

Therefore, x = 4 is the solution to the equation, indicating that 5 raised to the power of 4 equals 625.

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Answer:

None of the options provided (a, b, c, d) matches the correct probability. The correct probability is 1/18.

Step-by-step explanation:

The perimeter of the given window is 48 centimeter.

From the given figure,

Perimeter of window = 2(Length+Breadth)

= 2(10+14)

= 2×24

= 48 centimeter

Perimeter of house = 2(Length+Breadth)

= 2(37+35)

= 2×72

= 144 centimeter

Perimeter of roof = 2(Length+Breadth)

= 2(37+5)

= 2×42

= 84 centimeter

Therefore, the perimeter of the given window is 48 centimeter.

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The sum of the exterior angles in a regular 20-gon is given as follows:

360º.

An exterior angle of a polygon is defined as the angle between a side and its adjacent extended side.

The sum of exterior angles formula states the sum of all exterior angles in any polygon is 360°, no matter the number of sides.

For this problem, we have a 20-gon, that is a polygon of 20 sides, however, as the formula states, the sum of the exterior angles in a regular 20-gon is given as follows:

360º.

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