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What is the function of X?

Stels [109]

D the sent greater than or equal to 1

4 0

2 years ago

Write the expression that would represent “seven less than five times a number.”

Misha Larkins [42]

Answer:

7-5x

Step-by-step explanation:

3 0

3 years ago

A fence must be built to enclose a rectangular area of 20,000 ft^2. Fencing material costs $4 per foot for the two sides facing

Marysya12 [62]

The cost of the least expensive fence is $3200

Step-by-step explanation:

The given is:

A fence must be built to enclose a rectangular area of 20,000 ft²
Fencing material costs $4 per foot for the two sides facing north and south and $8 per foot for the other two sides

We need to find the cost of the least expensive fence

Assume that the length of each side opposite to North or South is x feet and the length of each other sides is y feet

∵ The length of the rectangle = x feet

∵ The width of the rectangle = y feet

∵ The rectangular area is 20,000 ft²

- Area of a rectangle = length × width

∴ x × y = 20,000

- Divide both sides by x to find y in terms of x

∴ $y=\frac{20,000}{x}$

The fence's length is equal to the perimeter of the rectangular area

∵ Perimeter of the rectangle = 2 length + 2 width

∴ Perimeter of the rectangle = 2x + 2y

∵ Fencing material costs $4 per foot for the two sides facing

North and South

∴ x costs $4 per foot

∵ The cost of the other two sides is $8 per foot

∴ y costs $8 per feet

The cost of the fence is the sum of the products of 4 , 2x and 8 , 2y

∵ The cost of the fence (C) = 4(2x) + 8(2y)

∴ C = 8x + 16y

- Substitute y by its value above

∴ $C=8x+16(\frac{20,000}{x})$

∴ $C=8x+\frac{320,000}{x}$

To find the least expensive differentiate C with respect to x and equate the answer by 0 to find the value of x

∵ $\frac{320,000}{x}$ can be written as $320,000x^{-1}$

∴ $C=8x+320,000x^{-1}$

∵ $\frac{dC}{dx}=8(1)x^{1-1}+320,000(-1)x^{-1-1}$

∴ $\frac{dC}{dx}=8-320,000x^{-2}$

- Equate $\frac{dC}{dx}$ by zero

∴ $8-320,000x^{-2}=0$

∵ $-320,000x^{-2}=-\frac{320,000}{x^{2}}$

∴ $8-\frac{320,000}{x^{2}}=0$

- Subtract 8 from both sides

∴ $-\frac{320,000}{x^{2}}=-8$

- Multiply both sides by x²

∴ - 320,000 = - 8x²

- Divide both sides by -8

∴ 40,000 = x²

- Take √ for both sides

∴ 200 = x

Substitute x in the equation of C to find the least cost of fence

∵ $C=8(200)+\frac{320,000}{(200)}$

∴ C = 1600 + 1600

∴ C = 3200

The cost of the least expensive fence is $3200

Learn more:

You can learn more about the differentiation in brainly.com/question/4279146

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5 0

2 years ago

The diameters of bolts produced in a machine shop are normally distributed with a mean of 5.18 millimeters and a standard deviat

dimulka [17.4K]

As per the concept of normal distribution, the two diameters of the bolt that has separate the top 3% and the bottom 3% are 5.2836 mm and 5.0764 mm respectively .

Normal distribution:

Normal distribution means the probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean and it has the bell shaped curve.

Given,

The diameters of bolts produced in a machine shop are normally distributed with a mean of 5.18 millimeters and a standard deviation of 0.07 millimeters.

Here we need to find the two diameters that separate the top 3% and the bottom 3% and these diameters could serve as limits used to identify which bolts should be rejected. we have also round off the result into nearest hundredth.

Here we have the given question with the values of,

The value of Mean is 5.18 millimeters

The value of Standard deviation is 0.07 millimeters.

Here we have to consider the following two cases, they are.

Case 1

We need to find x₁ such that that is P(X > x₁) = 3% when we convert it into decimal then we get P (X > x₁) = 0.03

So, as per the probability,

P (X ≤ x₁) = 1 - 0.03 = 0.97

So, z corresponding to the value of p = 0.97 is 1.48

Apply the given values to the formula of normal distribution then we get,

=> 1.48 = (x₁ - 5.18) /0.07

=> 0.1036 = x₁ - 5.18

Therefore, the value of x₁ is 5.2836

So, the diameter of the both with separate top 3% is 5.2836.

Case 2:

Next we have to take P(X < x₂) = 3% when we convert it into decimal then we get P (X < x₂) = 0.03

So, as per the given probability, the value of

P (X ≤ x₂) = 1 - 0.03 = 0.97

So, z corresponding to but here we have to use the negative because of the less than concept p = 0.97 is -1.48

Apply the values on the formula of normal distribution then we get,

-1.48 = (x₂ - 5.18) /0.07

Move the value to the other side

-0.1036 = x₂ - 5.18

When we simplify it,

x₂ = 5.0764

So, the diameter of the both with separate bottom 3% is 5.0764

To know more about Normal distribution here.

brainly.com/question/12421652

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7 0

11 months ago

How many gallons are equal to 27.3 hectoliters?

Mandarinka [93]

Answer:

721.19 gallons

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers