is there a difference in the amount of airborne bacteria between carpeted and uncarpeted rooms? in an experiment, 7 rooms were carpeted and 7 were left uncarpeted. the rooms are similar in size and function. after a suitable period of time, the concentration of bacteria in the air was measured (in units of bacteria per cubic foot) in all of these rooms. the data and summaries are provided: carpeted rooms: 184 22.0 uncarpeted rooms: 175 16.9 the researcher wants to investigate whether carpet makes a difference (either increases or decreases) in the mean bacterial concentration in air. the numerical value of the two-sample t statistic for this test is group of answer choices 0.414 0.858. 1.312 3.818

A, c, D

Step-by-step explanation:

A) we can sample these 7th graders as we are looking to study 7th graders.

b) The first 20 students could be from any grade and so this option wouldn't work.

c) Involves 7th graders.

d) involves 7th graders

E) The students could be any grade level on the debate team so, this option wouldn't work.

Using the completing the square method, the quadratic equation x²-5x=9 can be simplified to (x-2.5)²=15.25, and the solutions are x=2.5+√15.25 and x=2.5-√15.25.

To solve this quadratic equation using the completing the square method. Here are the steps

Move the constant term (in this case, 9) to the right-hand side of the equation

x² - 5x = 9 becomes x² - 5x - 9 = 0

To complete the square, we need to add and subtract a constant term inside the parentheses. The constant term we add is half of the coefficient of the x-term, squared. In this case, the coefficient of the x-term is -5, so we need to add and subtract (5/2)² = 6.25.

x² - 5x - 9 + 6.25 - 6.25 = 0

Rearrange the terms inside the parentheses to group the perfect square with the x-term

(x² - 5x + 6.25) - 15.25 = 0

Factor the perfect square trinomial inside the parentheses

(x - 2.5)² - 15.25 = 0

Add 15.25 to both sides of the equation

(x - 2.5)² = 15.25

Take the square root of both sides

x - 2.5 = ±√15.25

Add 2.5 to both sides

x = 2.5 ±√15.25

So the solutions to the equation x² - 5x = 9, using the completing the square method, are x = 2.5 + √15.25 and x = 2.5 - √15.25.

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--The given question is incomplete, the complete question is given

"Can anyone help? i need to solve these using the completing the square method

x²-5x = 9"--

We have found the n-vector b for which bc = p/(a), where p is the polynomial with coefficients c0, c1, ..., cn. Let's start by writing out the polynomial:

[tex]c0 + c1x + c2x^2 + ... + cnx^n[/tex]

The derivative of this polynomial with respect to x is:

[tex]c1 + 2c2x + 3c3x^2 + ... + ncnx^(n-1)[/tex]

At the point x=a, the derivative becomes:

[tex]c1 + 2c2a + 3c3a^2 + ... + ncn*a^(n-1)[/tex]

We want this to be a linear function of the coefficients c0, c1, ..., cn. That means we need to find a vector b such that:

[tex]c1 + 2c2a + 3c3a^2 + ... + ncna^(n-1) = b0c0 + b1c1 + ... + bncn[/tex]

Let's compare coefficients of c0, c1, ..., cn on both sides:

c1 = b1c1

2c2a = b2c2

[tex]3c3a^2 = b3c3[/tex]

...

[tex]ncna^(n-1) = bn*cn[/tex]

We can simplify these equations by dividing both sides by ci (assuming ci is not zero):

b1 = 1

b2 = 2a/c2

[tex]b3 = 3a^2/c3[/tex]

...

[tex]bn = n*a^(n-1)/cn[/tex]

So the vector b we're looking for is:

b = [1, 2a/c2, [tex]3a^2[/tex]/c3, ...,[tex]n*a^(n-1)/cn][/tex]

And if we multiply b by the coefficient vector c, we get:

bc = c1 + 2c2a + [tex]3c3a^2[/tex] + ...[tex]+ ncn*a^(n-1)[/tex] = the derivative of the polynomial at x=a

Therefore, we have found the n-vector b for which bc = p/(a), where p is the polynomial with coefficients c0, c1, ..., cn.

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For the point (7,8) in the coordinate plane which represents a ratio, Adela claims that you can find equivalent ratio by adding the same number to both coordinate of the point is incorrect.

Adela claim is not correct. To find an equivalent ratio, you should multiply (or divide) both coordinates by the same nonzero number instead of adding the same number.

1. The point (7,8) represents the ratio 7:8.

2. If we add the same number to both coordinates, let's say 2, we get the point (9,10), which represents the ratio 9:10.

3. We can check if 7:8 and 9:10 are equivalent ratios by cross-multiplying:

7 * 10 = 70 and 8 * 9 = 72. Since 70 ≠ 72, these ratios are not equivalent.

Therefore, Adela's claim is incorrect because adding the same number to both coordinates of the point does not result in an equivalent ratio. To find equivalent ratios, you should multiply (or divide) both coordinates by the same nonzero number.

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The expression that is equivalent to 3x – (2x + 4) + 5 is x+1 ( optionB)

Equivalent expressions are expressions that work the same even though they look different. If two algebraic expressions are equivalent, then the two expressions have the same value.

For example , 2a+6a is equivalent to 2a( 1+3) and they will surely have the same value when a value is replaced with a

3x – (2x + 4) + 5 = 3x-2x-4+5

= x-4+5

= x +1

therefore the equivalent of 3x – (2x + 4) + 5 is x+1

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The standard deviation of the sampling distribution is 2.53. It would not be appropriate to use a normal distribution to model the sampling distribution.

(a) When dealing with a sampling distribution, the mean of the sampling distribution (μ_x) is equal to the mean of the population (μ). In this case, the mean of the population is 65. Therefore, the mean of the sampling distribution is also 65.

To calculate the standard deviation of the sampling distribution (σ_x), you will use the following formula: σ_x = σ / √n, where σ is the standard deviation of the population and n is the sample size. In this case, the standard deviation of the population is 8 and the sample size is 10. So the standard deviation of the sampling distribution is:

σ_x = 8 / √10 ≈ 2.53

(b) The Central Limit Theorem states that the sampling distribution of the sample mean approaches a normal distribution as the sample size increases, regardless of the shape of the population distribution, provided that the population is not heavily skewed or has extreme outliers. Since the scores are extremely skewed left and the sample size is only 10, it would not be appropriate to use a normal distribution to model the sampling distribution. A larger sample size would be needed to use a normal distribution model.

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Answer:

20

Step-by-step explanation:

Answer:

23.50

Step-by-step explanation:

23.4571 rounded of to the nearest tenth 23.4+1

Answer:  the correct answer is:

a = 14, b = 64, c = 76, d = 20, e = 90

Step-by-step explanation: can i get brainliest :D

The correct inequality is:

A. 0.095x < 65.00.

To determine the inequality that represents the numbers of kilowatt-hours a customer could use in a month for the cost to be less than $65.00, we need to look for the rate at which the cost of electricity changes with the amount of electricity used.

From the table, we can see that the cost of electricity increases as the amount of electricity used increases.

We can also see that the cost per kilowatt-hour (the rate) is not constant. For example, the cost per kilowatt-hour for the first month is:

27.55 / 290 ≈ 0.095

But for the fourth month, it is:

47.50 / 500 ≈ 0.095

This means that the rate is not constant, and we cannot simply use a proportion to determine the numbers of kilowatt-hours that will result in a cost of less than $65.00.

However, we can use the data to create an inequality that represents the numbers of kilowatt-hours that will result in a cost less than $65.00. We can start by finding the highest cost per kilowatt-hour:

43.70 / 460 ≈ 0.095

This means that the cost per kilowatt-hour is always less than or equal to 0.095.

Next, we can set up the inequality:

0.095x < 65.00

This inequality represents the numbers of kilowatt-hours that will result in a cost less than $65.00, because if the cost per kilowatt-hour is always less than or equal to 0.095, then the total cost will be less than $65.00 if and only if the number of kilowatt-hours used is less than 684.21 (which is the result of dividing $65.00 by 0.095).

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Thus, 25.13 cubic inches is the closest estimate for the ice cream's overall volume.

Volume is a mathematical concept that describes how much space a three-dimensional object occupies. It is frequently expressed in terms of cubic units like cubic metres (m3), cubic feet (ft3), or cubic centimetres (cm3). Depending on the shape of the object, different formulas can be used to determine its volume. Consider this: The formula V = l w h, where l has been the length, w is the broad, and h corresponds to the height of the rectangular prism (box), gives the volume of the object. A sphere's volume can be calculated using the method V = (4/3)r3, where r is the sphere's radius.

given

The formula for a cone's volume is as follows, assuming that the ice cream has the correct circular cone shape with radius r = 2 in and height h = 6 in:

[tex]V = (1/3) * \pi * r^2 * h[/tex]

Inputting the values provided yields:

[tex]V = (1/3) * \pi * (2 in) * (2 in) * (6 in)[/tex] = 25.13 cubic inches

Thus, 25.13 cubic inches is the closest estimate for the ice cream's overall volume.

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The complete question is:-  

r = 2 in.

h = 6 in.

Which is closest to the total volume of the ice

cream?

Answer: 32000

Step-by-step explanation: 40000 x 80% because you still have 80 percent of that budget so you minus 20 for 100.

Using the federal list, the total amount of exemptions that Jerry would be allowed is $29,800.

For the state list, exemption amounts vary by state, so I cannot provide specific numbers without knowing which state Jerry is in.

To determine the total amount of exemptions Jerry would be allowed using the federal list and state list, we first need to examine the value of each asset. Jerry has a house with equity of $15,000, a car with equity of $2,500, household goods worth $6,000, and tools worth $5,800.

Using the federal list, the exemptions include:
1. Homestead exemption: up to $25,150 for the house equity
2. Motor vehicle exemption: up to $4,000 for the car equity
3. Household goods exemption: up to $13,400 (no single item over $625)
4. Tools of the trade exemption: up to $2,525 for tools needed for business

Jerry's federal exemptions would be:
1. $15,000 for the house (within the $25,150 limit)
2. $2,500 for the car (within the $4,000 limit)
3. $6,000 for household goods (within the $13,400 limit)
4. $5,800 for the tools (exceeds the $2,525 limit)

Using the federal list, the total amount of exemptions that Jerry would be allowed is $29,800 (15,000 + 2,500 + 6,000 + 2,525).

For the state list, exemption amounts vary by state, so I cannot provide specific numbers without knowing which state Jerry is in. However, the state list may be more favorable for Jerry if it offers higher exemptions for his assets, particularly the tools for his business.

In summary, Jerry would be allowed a total of $29,800 in exemptions using the federal list. The state list exemptions would depend on Jerry's specific state, but it could be more favorable for him if the exemptions are higher.

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The total amount of exemptions that Jerry would be allowed using the federal list is $13,100.

Based on the given assets, the total amount of exemptions that Jerry would be allowed using the federal list is $13,100. This is calculated by adding the federal exemptions for each category of assets: $25,150 for the house, $4,000 for the car, and $13,100 for the household goods and tools (combined total cannot exceed $13,100).
The state list varies depending on the state where Jerry resides. Without knowing the state, it is impossible to provide an accurate answer. However, it is generally true that the state list can be more favorable for the debtor, as some states have higher exemption amounts or allow for additional exemptions that are not available under federal law. Jerry should consult with a bankruptcy attorney in his state to determine the specific exemptions available to him.

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The value of coordinate M and K are,

M = (25, 0)

K = (2b + 4c - 25, 2d)

Given that;

In KLMO,

OM = 25

L = (2b + 4c , 4d)

Hence, We can formulate;

The value of coordinate of M is,

M = (25, 0)

Since, M lies on x - axis.

Let the coordinate of K is,

K = (x, y)

Hence, Midpoint of LO is same as midpoint of KM.

Midpoint of LO is,

(0 + 2b + 4c / 2, 4d/2)

(b + 2c, 2d)

Midpoint of KM is

(x + 25/2, y + 0/2)

(x + 25/2 , y/2)

By comparing,

x + 25/2 = b + 2c

x + 25 = 2b + 4c

x = 2b + 4c - 25

y/2 = 2d

y = 2d

Thus, the coordinate of K is,

K = (2b + 4c - 25, 2d)

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Jack can sell 12 bird feeders with 4 lb of birdseed. We can use Proportion method to calculate this :

Assuming that Jack mixes 1/3 pound of birdseed for each bird feeder, we can find out how many bird feeders he can sell with 4 pounds of birdseed by using a proportion.

Let x be the number of bird feeders Jack can make with 4 pounds of birdseed. We can set up the proportion:

1/3 pounds of birdseed per bird feeder = 4 pounds of birdseed / x bird feeders.

Simplifying this equation, we get:

1/3 = 4/x

To solve for x, we can cross-multiply:

1x = 12

x = 12

Therefore, Jack can make and sell 12 bird feeders with 4 pounds of birdseed.

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The velocity of the particle at time t is given by [tex]v(t) = 70t/(3t^2 + 8)^2.[/tex]

The expression for the acceleration of the particle is a(t) [tex]= (210t^2 + 1120)/(3t^2+8)^3.[/tex]

A) To find the velocity of the particle, we need to take the derivative of its position with respect to time:

[tex]X(t) = (t^2 - 9)/(3t^2 + 8)[/tex]

[tex]v(t) = dX/dt = [(2t)(3t^2+8) - (t^2-9)(6t)]/(3t^2+8)^2[/tex]

[tex]v(t) = (6t^3 + 16t - 6t^3 + 54t)/(3t^2 + 8)^2[/tex]

[tex]v(t) = 70t/(3t^2 + 8)^2[/tex]

Therefore, the velocity of the particle at time t is given by[tex]v(t) = 70t/(3t^2 + 8)^2.[/tex]

B) To determine whether the particle is moving toward or away from the origin at time t = 2, we need to examine the sign of the velocity v(2). Plugging t = 2 into the expression for v(t), we get:

[tex]v(2) = 70(2)/((3(2)^2 + 8)^2) = 280/169[/tex]

Since v(2) is positive, the particle is moving away from the origin at time t = 2.

C) The acceleration of the particle is given by the derivative of its velocity with respect to time:

[tex]v(t) = 70t/(3t^2 + 8)^2[/tex]

[tex]a(t) = dv/dt = (70(3t^2+8)^2 - 2(70t)(2t)(3t^2+8))/(3t^2+8)^4[/tex]

[tex]a(t) = (210t^2 + 1120)/(3t^2+8)^3[/tex]

Therefore, the expression for the acceleration of the particle is [tex]a(t) = (210t^2 + 1120)/(3t^2+8)^3[/tex]. To find the value of a(2), we plug in [tex]t = 2:a(2) = (210(2)^2 + 1120)/(3(2)^2+8)^3 = 175/677[/tex]

D) To find the position that the particle approaches as t approaches infinity, we examine the behavior of X(t) as t gets very large. We can do this by looking at the leading term of the numerator and denominator of X(t) as t approaches infinity:

[tex]X(t) = (t^2 - 9)/(3t^2 + 8)[/tex]

As t approaches infinity, the numerator is dominated by the t^2 term, and the denominator is dominated by the 3t^2 term. Therefore, as t approaches infinity, X(t) approaches:

[tex]X(infinity) = t^2/3t^2 = 1/3[/tex]

So the particle approaches the point x = 1/3 as t approaches infinity.

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To determine whether the function f(2) converges or diverges, we need to evaluate the limit of the function as x approaches 2. We can rewrite the function as:

f(2) = 1 / (x² + √x) = 1 / (x² + x^(1/2))

As x approaches 2, both x² and x^(1/2) approach 2, so we can substitute 2 for both of these terms:

f(2) = 1 / (2² + 2^(1/2)) = 1 / (4 + 1.414) ≈ 0.176

Therefore, f(2) converges to a finite value of approximately 0.176, and does not diverge.

Based on the given information, let's analyze the function f(x) = 1 / (x² + √x). To determine if the function converges or diverges, we can examine its behavior as x approaches infinity.

As x gets larger, both x² and √x increase, but x² increases at a much faster rate. Therefore, the denominator (x² + √x) will become larger and larger as x approaches infinity. Consequently, the value of the function f(x) = 1 / (x² + √x) will approach 0.

Since the function approaches 0 as x goes to infinity, we can conclude that the function f(x) = 1 / (x² + √x) converges.

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The statement that best describes the information is:

-If the total number of gigabytes stored exceeds 750, then each gigabyte beyond 750 costs 5 cents.

This is because the equation c = 0.05(g - 750) + 19.95 applies only when the number of gigabytes (g) exceeds 750. For every gigabyte over 750, an additional 5 cents is charged, while the base cost of $19.95 is for the first 750 gigabytes of storage.

If the customer needs to store more than 750 gigabytes, the annual cost is determined by the equation c = 0.0 ,5(g - 750) + 19.95, where c is the annual cost in dollars, and g is the total number of gigabytes of data stored

The statement that best describes this information is:

The Data-Safe Company offers online data storage services with an annual fee of ,$19.95 for up to 750 gigabytes of storage. If a customer requires more than 750 gigabytes of storage,. an additional fee of $0.05 per gigabyte is charged for the excess storage beyond the initial 750 gigabytes.

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Complete question

Data-Safe Company leases online data storage

space. A customer can store up to 750

gigabytes of computer files for an annual fee of

$19.95. If the number of gigabytes exceeds 750,

then the equation c=0.05(g - 750) + 19.95

determines the annual cost, c. in dollars in terms

of g, the total number of gigabytes of data

stored. Which statement best describes this

information?

-If the total number of gigabytes stored is

more than 750, then every gigabyte stored

costs 5 cents.

-If the total number of gigabytes stored

exceeds 750, then each gigabyte beyond

750 costs 5 cents.

B

-The first 750 gigabytes stored costs 5 cents

each, after which there is an additional cost

of $19.95

-Every gigabyte of data stored costs 5 cents

no matter how many gigabytes are stored.

The area of the unbounded region R between the graph of y=1/(xln(x))² and the x-axis for x≥3 is 1/ln(3) square units. The integral was found by substitution and evaluated at the interval limits.

To find the area of the region R, we need to integrate the function y = 1/(x ln(x))² with respect to x over the interval x≥3.

Let's first find the indefinite integral

∫ 1/(x ln(x))₂ dx = ∫ u₂ du [where u = ln(x)]

= - u⁻¹ + C

= - ln(x)⁻¹ + C

Now, to find the definite integral, we need to evaluate this expression at the upper and lower bounds of the interval x≥3

[tex]\int\limits^ \infty} _3[/tex]1/(x ln(x))² dx = [- ln(x)⁻¹[tex]]^ \infty} _3[/tex]

= [- ln(∞)⁻¹] - [- ln(3)⁻¹]

= 0 - (-1/ln(3))

= 1/ln(3)

Therefore, the area of the region R is 1/ln(3) square units.

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The road with alternating white and black stripes and each 50 cm wide is 7.5 m wide.

The road consists of alternating white and black stripes

No. of white stripes = 8

As the first and last stripe is white so in between the black stripes will be 7

No. of black stripes = 7

Total no. of stripes = 15

Width of black stripe = 50 cm

Width of white stripe = 50 cm

Width of whole road = total no. of stripes × width of each stripe

Width of whole road = 15 × 50

Width of whole road = 750 cm

To convert m into cm

Now, 1 m = 100 cm

1 cm = 1/100 m

750 cm = 750/100 m

750 cm = 7.5 m

Hence the width of the road is 7.5 m

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The one possible value of y, will be 2. Option C is correct.

We have f(x) = x² + 28, and f(3y) = 2f(y). Substituting 3y for x in the definition of f, we get;

f(3y) = (3y)² + 28 = 9y² + 28

Substituting y for x in the definition of f, we get;

f(y) = y² + 28

Using the given equation, we have;

2(y² + 28) = 9y² + 28

Expanding and simplifying, we get;

0 = 7y² - 56

Dividing by 7, we get:

y² - 8 = 0

Factoring, we get;

(y + 2)(y - 2) = 0

So y = -2 or y = 2. Since we are looking for only one possible value of y is 2.

Hence, C. is the correct option.

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The upper quartile of the time spent reading is 300.

We have,

The upper quartile, also known as the third quartile, is a measure of central tendency that divides a data set into four equal parts.

It represents the data point that separates the top 25% of the data from the bottom 75%.

Now,

From the box pot.

Median = 250

Lower quartile = 100

Upper quartile = 300

Thus,

The upper quartile is 300.

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(3.4a – 1.7b) and (–1.7b 4.9a) and (5.9a – 5.6b) are equivalent expressions.

The question presents a list of six expressions. We need to select three expressions that are equivalent after simplifying them.

One of the expressions is (3.4a - 1.7b), and another is (-1.7b + 4.9a). These two expressions can be simplified to 2.4a - 1.7b.

Another expression is (2.5a - 3.9b), and another is (-3.9b + a). These two expressions can be simplified to 3.5a - 3.9b.

The third expression is 5.9a - 5.6b, which cannot be simplified further.

The three expressions that are equivalent after simplifying are (3.4a - 1.7b) and (-1.7b + 4.9a), (2.5a - 3.9b) and (-3.9b + a), and 5.9a - 5.6b.

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x = 1

[tex]2x + \dfrac{1}{4} = \dfrac{1}{4}x + 2[/tex]

1. subtract (1/4)x from both sides

[tex]\dfrac{7}{4}x + \dfrac{1}{4} = 2[/tex]

2. subtract 1/4 from both sides

[tex]\dfrac{7}{4}x = \dfrac{7}{4}[/tex]

3. multiply both sides by the reciprocal of x's coefficient

The reciprocal of [tex]\frac{\bold{7}}{\bold{4}}[/tex] is [tex]\frac{\bold{4}}{\bold{7}}[/tex].

[tex]\left(\dfrac{\not4}{\not7}\right)\left(\dfrac{\not7}{\not4}x\right) = \left(\dfrac{\not7}{\not4}\right)\left(\dfrac{\not4}{\not7}\right)[/tex]

[tex]\boxed{x = 1}[/tex]

Answer:

C. An obtuse triangle has two angles less than 90 degrees and one angle greater than 90 degrees.

If we plan to buy more than 10 gallons of gas, it is worth it to buy the car wash, assuming that the cost of the car wash is $2.

The car wash costs $7, and the price per gallon of gas with the car wash is $3.19, while the price per gallon of gas without the car wash is $3.39. Let's assume that we buy x gallons of gas, then the total cost of buying gas with the car wash would be:

Total cost with car wash = 7 + 3.19x

The total cost of buying gas without the car wash would be:

Total cost without car wash = 3.39x

To determine when it is worth it to buy the car wash, we need to find when the total cost with the car wash is less than the total cost without the car wash:

7 + 3.19x < 3.39x

Solving for x:

7 < 0.2x

x > 35

This means that if we plan to buy more than 35 gallons of gas, it is worth it to buy the car wash.

Now, let's consider the scenario where the car wash costs $2. The total cost of buying gas with the car wash would be:

Total cost with car wash = 2 + 3.19x

To determine when it is worth it to buy the car wash in this scenario, we need to find when the total cost with the car wash is less than the total cost without the car wash:

2 + 3.19x < 3.39x

Solving for x:

2 < 0.2x

x > 10

This means that if we plan to buy more than 10 gallons of gas, it is worth it to buy the car wash, assuming that the cost of the car wash is $2.

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