In a study conducted by the Department of Mechanical Engineering at Virginia Tech, the steel rods supplied by two different companies were compared. Ten sample springs were made out of the steel rods supplied by each company, and a measure of flexibility was recorded for each. The data are as follows:
Company A: 9.3; 8.8; 6.8; 8.7; 8.5; 6.7; 8.0; 6.5; 9.2; 7.0
Company B: 11.0; 9.8; 9.9; 10.2; 10.1; 9.7; 11.0; 11.1; 10.2; 9.6
i. Calculate the sample mean and median for the data for the two companies.
ii. Plot the data for the two companies on the same line/chart and give your impression regarding any apparent differences between the two.
iii. Is there any relation between the two companies? Compare using the 90% confidence interval of the mean.
iv. Which company you will recommend

1. Therefore, the exact value of cos(105°) is (√2 - √6)/4.

2. Therefore, the exact value of sin(75°) is (√6 + √2)/4.

3. Therefore, the exact value of tan(105°) is (√3 + 1)/(3 - √3).

4. Therefore, the exact value of cos(105°)cos(15°) is (2 + 2√3)/8.

A branch of mathematics known as trigonometry is concerned with the study of triangles and the correlations between their sides and angles.

It entails computing different triangle measurements and attributes using trigonometric functions including sine, cosine, and tangent.

Trigonometry is an essential component of calculus and other advanced mathematical studies, and it has applications in many disciplines including engineering, physics, navigation, astronomy, and architecture.

1. We can use the formula cos(A + B) = cos(A)cos(B) - sin(A)sin(B) with A = 60° and B = 45°. Then:

cos(105°) = cos(60° + 45°)

= cos(60°)cos(45°) - sin(60°)sin(45°)

= (1/2)(√2/2) - (√3/2)(√2/2)

= (√2 - √6)/4

Therefore, the exact value of cos(105°) is (√2 - √6)/4.

2. We can use the formula sin(A + B) = sin(A)cos(B) + cos(A)sin(B) with A = 45° and B = 30°. Then:

sin(75°) = sin(45° + 30°)

= sin(45°)cos(30°) + cos(45°)sin(30°)

= (√2/2)(√3/2) + (√2/2)(1/2)

= (√6 + √2)/4

Therefore, the exact value of sin(75°) is (√6 + √2)/4.

3. We can use the formula tan(A + B) = (tan(A) + tan(B))/(1 - tan(A)tan(B)) with A = 60° and B = 45°. Then:

tan(105°) = tan(60° + 45°)

= (tan(60°) + tan(45°))/(1 - tan(60°)tan(45°))

= (√3 + 1)/(3 - √3)

Therefore, the exact value of tan(105°) is (√3 + 1)/(3 - √3).

4. We can use the formula cos(A + B) = cos(A)cos(B) - sin(A)sin(B) with A = 60° and B = -45°. Then:

cos(105°)cos(15°) = cos(60° - 45°)cos(15°)

= [cos(60°)cos(-45°) - sin(60°)sin(-45°)]cos(15°)

= [(1/2)(√2/2) - (√3/2)(-√2/2)]cos(15°)

= (√2 + √6)/4 * cos(15°)

= (√2 + √6)/4 * (√6 + √2)/4

= (2 + 2√3)/8

Therefore, the exact value of cos(105°)cos(15°) is (2 + 2√3)/8.

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Answer:

The discriminant is:

(-3)^2 - 4(1)(18) = 9 - 72 = -63

Since this discriminant is negative, f(x) does not have any real number solutions.

The number of gallons of gas Brynen will use in driving to and from work, during the week, obtained using arithmetic operations is 7 5/7 gallons

Arithmetic operations are operations involving addition, subtraction, multiplication, and division.

The distance Brynen travels each way to his new job = 27 miles

The distance his car gets per gallon of gas = 35 miles

The number of gallons he will use in a week (five days of driving in the week), can therefore, be found by arithmetic operations follows;

The distance Brynen travels = 27 × 2 × 5 = 270 miles

The number of gallons = 270 miles/(35 miles/gallon) = 270/35 = 7 25/35

7 25/35 = 7 5/7

The volume of gas he will use to and from work this week is; 7 5/7 gallons

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The values of x, y, and z based on the system of equations will be (-2,4,7).

x + 3y + 5z = 45

6x - 3y + 2z = - 10

------------------------add

7x + 7z = 35

6x - 3y + 2z = -10

-2x + 3y + 8z = 72

----------------------add

4x + 10z = 62

7x + 7z = 35....multiply by 4

4x + 10z = 62...multiply by -7

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

28x + 28z = 140 (result of multiplying by 4)

-28x - 70z = - 434 (result of multiplying by -7)

--------------------add

- 42z = - 294

z = -294/-42

z = 7

4x + 10z = 62

4x + 10(7) = 62

4x + 70 = 62

4x = 62 - 70

4x = - 8

x = -8/4

x = -2

x + 3y + 5z = 45

-2 + 3y + 5(7) = 45

-2 + 3y + 35 = 45

3y + 33 = 45

3y = 45 - 33

3y = 12

y = 12/3

y = 4

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Solve the following system of equations algebraically for all values of x,y and z

x+3y+5z=45

6x-3y+2z=-10

-2x+3y+8z=72

The maximum profit that for the equation p(x) = 2800x - 85x² - x³ - 109000 is $672500

An exponential equation is an expression that shows how numbers and variables using mathematical operators.

Given the profit function:

p(x) = 2800x - 85x² - x³ - 109000

The profit is maximum at:

p'(x) = 0

p(x) = 2800 + 170x - 3x²

2800 + 170x - 3x² = 0

x = 70

p(70) = 2800(70) - 85(70)² - (70)³ - 109000 = 672500

The maximum profit is $672500

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B is a 2 by 2 matrix, and the determinant of B written as |B| is equal to -1.

We can find |B|, the determinant of the matrix B by subtracting the multiple of row column and row 2 column 1 from the multiple of row column 1 and row 2 column 2 as follows:

|B| = (-2 × -2) - (1 × 5)

|B| = 4 - 5

|B| = -1.

Therefore, the determinant of the 2 by 2 matrix B written as |B| is equal to -1.

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Therefore, the volume of the composite solid is approximately 1357.28 cubic feet, rounded to the nearest hundredth.

Volume is a measure of the amount of space occupied by an object or a substance. In other words, it is the three-dimensional space that an object or substance occupies. The SI unit for volume is cubic meters (m³), although other units such as cubic centimeters (cm³) and liters (L) are also commonly used.

Here,

The composite solid is made up of a hemisphere and a cone with the same base radius and height. The volume of the hemisphere is given by (2/3)πr³, and the volume of the cone is given by (1/3)πr²h, where r is the radius and h is the height. Given that the radius is 6 feet and the height is 12 feet, we can find the volumes of the hemisphere and the cone as follows:

Volume of hemisphere = (2/3)π(6³)

= 288π cubic feet

Volume of cone = (1/3)π(6²)(12)

= 144π cubic feet

The total volume of the composite solid is the sum of the volumes of the hemisphere and the cone, which is:

Total volume = Volume of hemisphere + Volume of cone

= 288π + 144π

= 432π

To find the numerical value of this volume, we can use the approximation π ≈ 3.14 and round the result to the nearest hundredth:

Total volume ≈ 432(3.14)

= 1357.28 cubic feet

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The  required area of the rectangle is 8 sq. units

Any mathematical statement with numbers, variables, and an arithmetic operation between them is an expression or algebraic expression. For instance, the expression 4m + 5 is one in which the terms 4m and 5 and the variable m are separated by the arithmetic sign +.

From the diagram

Length = 4 units, width = 2 units

Area of rectangle = length×width

Area of rectangle = 4×2

Area of rectangle = 8 sq. units

Thus, required area of the rectangle is 8 sq. units

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the deductible, and the coinsurance. Here are the steps to calculate the total out-of-pocket expense: the total out-of-pocket expense for one month is $ [tex]154[/tex] .

To calculate the out-of-pocket expense for one month, we need to take into account the monthly premium.

Step 1: Calculate the deductible

The deductible is the amount that the insured person needs to pay before the insurance starts covering the costs.

In this case, the deductible is $500 because that's the threshold for the 90% coverage. Since the family will fill 6 prescriptions per month, we need to calculate the average cost per prescription:

Average cost per prescription = Total prescription costs / Number of prescriptions

Average cost per prescription = $ [tex]850 / 6 = $141.67[/tex]

Since the deductible is $500, the insurance will cover 90% of the first $500, which is $450. The remaining $50 will be paid by the insured person. Therefore, the deductible is $  [tex]500 - $450 = $50.[/tex]

Step 2: Calculate the coinsurance

After the deductible is met, the insurance will cover 80% of the remaining prescription costs, and the insured person will be responsible for the remaining  [tex]20[/tex] %.

To calculate the coinsurance, we need to subtract the deductible from the total prescription costs and multiply the result by 0.2:

Coinsurance = (Total prescription costs - Deductible) x 0.2

Coinsurance = [tex]($850 - $500) \times 0.2[/tex]

Coinsurance = $ [tex]70[/tex]

Step 3:

Calculate the total out-of-pocket expense

The total out-of-pocket expense is the sum of the monthly premium, the deductible, and the coinsurance:

Total out-of-pocket expense = Monthly premium + Deductible + Coinsurance

Total out-of-pocket expense = $  [tex]34 + $50 + $70[/tex]

Total out-of-pocket expense = $154

Therefore, the total out-of-pocket expense for one month is $ [tex]154[/tex] .

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The equation of the quadratic with a directrix of x = 2 and vertex of (0 , 0)  is: y² =  -8x

The equation of the quadratic with a directrix of y = 4 and vertex of (1, 3)  is: (x - 1)² = -4 (y - 3)

Quadratic equation when the directrix is at x direction is of the form:

(y - k)² =  4P (x - h)

OR

standard vertex form, x = a(y - k)² + h     where a = 1/4p

The vertex

v (h, k) = (0, 0)

P in this problem, is the distance between the vertex and the directrix

P = 0 - 2 = -2

substitution of the values into the equation gives

(y - k)² =  4P (x - h)

(y - 0)² =  4 x -2 (x - 0)

y² =  -8x

Quadratic equation when the directrix is at y direction is of the form:

(x - h)² =  4P (y - k)

OR

standard vertex form, y = a(x - h)² + k     where a = 1/4p

The vertex

v (h, k) = (1, 3)

P in this problem, is the distance between the vertex and the directrix

P = 3 - 4 = -1

substitution of the values into the equation gives

(x - h)² =  4P (y - k)

(x - 1)² =  4 * -1 (y - 3)

(x - 1)² = -4 (y - 3)

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The polygons that can be formed by the intersection of a plane and a cylinder either parallel or perpendicular to the base include :

If a plane intersects three distinct vertices of the cube while bypassing any other vertices, a triangle is produced. To visualize this, suppose a corner of the cube were removed with a knife; picture that cut surface as a triangle.

On the other hand, if a plane coincides with four points on the cube and outlines a square shape, it creates what's called a "square cross-section." This transpires when said plane parallels one side of the cube while intersecting only the midpoints of its opposite face's edges.

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Full question is:

Select all the polygons that can be formed by the intersection of a plane and a cylinder either parallel or perpendicular to the base

A triangle

B square

C. rectangle

D pentagon

E circle

Total area to paint: (15 + 10) - 1.5 = 23.5 sq ft

Calculate the area of each wall, subtract the door area, and sum the areas.

Front and back walls: (3 * 2.5) * 2 = 15 sq ft

Next, we calculate the area of the side walls:

Side walls: (2 * 2.5) * 2 = 10 sq ft

Door area: 1.5 * 1 = 1.5 sq ft

Total area to paint: (15 + 10) - 1.5 = 23.5 sq ft

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The Complete Question

Kara wants to paint the four outside walls of her dog's house, excluding the roof and door. The dog house measures 3 feet in length, 2 feet in width, and 2.5 feet in height. The door is 1.5 feet tall and 1 foot wide. What is the area of the surface she needs to paint?

Answer:

To determine the longest rod that can be carried to the loading dock, we want to find the shortest distance from point T to line segment CD. We can use the Pythagorean theorem for this.

First, we need to find the equation of the line containing segment CD. We can find the slope of the line CD as:

m = (y2 - y1) / (x2 - x1) = (36 - 48) / (48 - 0) = -12/48 = -1/4

where (x1, y1) = (0, 48) and (x2, y2) = (48, 36).

Using point-slope form, we get the equation of the line CD as:

y - 48 = (-1/4)(x - 0)

y = (-1/4)x + 48

Now, we can find the perpendicular distance from point T to the line CD as follows:

d = |(-1/4)(30) + 72 - 48| / sqrt((-1/4)^2 + 1)

d = 42 / sqrt(17) ≈ 10.21

Therefore, the longest rod that can be carried to the loading dock is approximately 10.2 inches long (rounded to the nearest tenth of an inch).

Answer:

$140,000

Step-by-step explanation:

7*20,000 = 140,000

Answer:

108

You rounded to the nearest tens place.

The 0 in the tens place rounds up to 1

Step-by-step explanation: because the digit to the right in the ones place is 8.

110

When the digit to the right is 5 or greater we round away from 0.

108 was rounded up and away from zero to 110

The grams of each food she feeds this group of rats each day is 80 grams of food A and 100 grams of food B each day.

Let us consider that the researcher feeds x grams of food A and y grams of food B each day. Then we can restructure the  two equations on the basis of  the amount of niacin and retinol present in the food
0.11x + 0.35y = 28.4 (equation 1)
190x + 95y = 37,335 (equation 2)

We can evaluate this system of equations applying the substitution or elimination method.
Let us apply substitution method:
In case of equation 1, we can evaluate concerning x:
x = (28.4 - 0.35y) / 0.11
Staging this value for x in equation 2
190[(28.4 - 0.35y) / 0.11] + 95y
= 37,335
Applying simplification and evaluating for y
y = 100
Staging this value for y in equation 1 to evaluate x

x = 80

Then, the researcher feeds 80 grams of food A and 100 grams of food B each day.
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Answer:

25$ if the tickets were involved it would be 70$

Santiago would have to pay $87 in total if he bought 6 snacks for everyone to share. The cost increases to $60 + 4.5*x when a variable number of snacks, represented by x, are bought.

The topic of this question is

Mathematics

, specifically about using multiplication and addition in problem-solving.

Firstly, Santiago is going to see a movie with his 3 kids. Therefore, he needs to buy 4 tickets. If each ticket costs $15, then the total cost for movie tickets will be 4 * 15 = $60.

Secondly, if Santiago buys 6 snacks for everybody to share with each snack costing $4.50, the total cost for snacks will be 6 * 4.5 = $27. The total money Santiago would have to pay for his family would then be the sum of the costs of the tickets and snacks, which is 60 + 27 = $87.

Regarding the case when Santiago bought x snacks for everybody to share, the total cost would become 60 + 4.5*x. This formula gives the total cost based on the given number of snacks.

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Thus, 9 percent of the total dance tickets available is found to be purchased in advance.

Although the usage of percent and percentage differs slightly, they both signify the same thing. It is customary to use percent or the symbol (%) along with a numerical value. One tenth of something is one percent.

Given data:

Total dance tickets = 200

Advanced purchased tickets = 18

Let x be the percentage of advance booked tickets.

Then,

x% of 200 = 18

x*200 / 100 = 18

2x = 18

x = 18/2

x = 9%

Thus, 9 percent of the total dance tickets available is found to be purchased in advance.

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The angle of the turn at Deer Trail is of 105 degrees.

Notice that both of the lines that go up to the left are parallel, thus, the angles formed betwen the intersections are all equal (for the respective lines).

Now, also know that two adjacent angles in an intersection should add up to 180°.

We can see that the angle to the right of deer trail has a measure of 75°, then the angle to the left (which is adjacent) must have a measure M such that:

M + 75° = 180°

M = 180° - 75°

M = 105°

That is the angle of the turn.

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Answer:

A) m∠3 + m∠6 = 90

Step-by-step explanation:

Angles 3 and 6 are complementary angles. This means they add up to 90 degrees. Since you know the angle that is a right angle due to the box, you know these angles add up to 90 degrees

Answer:

The quotient is

[tex]8 {x}^{2} + 15x - \frac{1}{8} [/tex]

and the remainder is

[tex] \frac{63}{64} [/tex]

Answer:

the car's angular speed is 72,000π radians per hour.

the car's linear speed is approximately 100.53 miles per hour.

Step-by-step explanation:

To find the car's angular speed in radians per hour, we can start by finding the angular speed in radians per second.

The formula for angular speed is:

ω = 2πf

where ω is the angular speed in radians per second, and f is the frequency or rate of rotation in revolutions per second.

In this case, the wheel is spinning at a rate of 10 revolutions per second, so:

ω = 2π(10) = 20π radians per second

To convert this to radians per hour, we can multiply by the number of seconds per hour:

20π radians per second × 3600 seconds per hour = 72,000π radians per hour

To find the car's linear speed in miles per hour, we can use the formula:

v = rω

where v is the linear speed, r is the radius of the wheel, and ω is the angular speed in radians per second.

The radius of the wheel is half the diameter, or 9 inches. To convert this to miles, we can divide by 12 and then by 5280:

9 inches ÷ 12 inches per foot ÷ 5280 feet per mile = 0.000142045 miles

Now we can substitute the values we have found:

v = (0.000142045 miles) × (18/2 inches) × (20π radians per second)

v ≈ 100.53 miles per hour

Answer:

(i) 10 revolutions = 10(2π) = 20π radians

10 revolutions/sec =

(20π radians/sec)(3,600 sec/hr) =

72,000π radians/hr

(ii) C = 18π inches

10 revolutions × 18π inches =

180π inches

(180π in./sec)(3,600 sec/hr) =

(648,000π in./hr)(1 mi./63,360 in.)

= 225π/22 miles/hour

= about 32.13 miles/hour

The minimum grade you need to get a B in the course is given as follows:

x = 80.625.

The mean of a data-set is given by the sum of all observations in the data-set divided by the number of observations, which is also called the cardinality of the data-set.

The grades and their percentages are given as follows:

You want a grade of 80, hence the minimum test average is obtained as follows:

0.15 x 73 + 0.2 x 79 + 0.25 x 84 + 0.4x = 80

47.75 + 0.4x = 80

x = (80 - 47.75)/0.4

x = 80.625.

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The areas of the trapezoids is,

A = 48 sq units.

Since, The formula to find the area of a trapezoid of a trapezoid is,

⇒ A = 1/2(b₁ + b₂ )h.

Hence, it is stated that the height of each unit is 2.

Now let's substitute the variables in the formula with the actual bases and heights as;

A = 1/2(8 + 4)8,

A = 6 × 8,

A = 48 sq units.

Thus, the areas of the trapezoids is,

A = 48 sq units.

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The three types of rock are igneous, sedimentary, and metamorphic.

There are three types of rocks as explained below.

Igneous rocks are formed from the cooling and solidification of molten rock, either on the Earth's surface (extrusive) or beneath the surface (intrusive). Examples of igneous rocks include basalt, granite, and pumice.

Sedimentary rocks are formed from the accumulation and cementation of sediment particles (such as sand, silt, and clay) or the precipitation of minerals from a solution. Examples of sedimentary rocks include sandstone, limestone, and shale.

Metamorphic rocks are formed from the alteration of pre-existing rocks by heat, pressure, and chemical reactions. Examples of metamorphic rocks include marble, slate, and gneiss.

The rock cycle is the process by which one type of rock can be changed into another type of rock.

The rock cycle involves three main processes:

Therefore, one type of rock can be changed into another type of rock through the rock cycle by undergoing weathering, erosion, deposition, lithification, metamorphism, melting, and solidification, depending on the specific conditions and processes involved.

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The absence of the value 105.0 from the interval shows that the medication therapy significantly reduces wake time.

In statistics, mean is a measure of central tendency that represents the average value of a set of data. It is commonly referred to as the "arithmetic mean" or simply the "average." To calculate the mean, you add up all the values in the data set and divide the total by the number of values. For example, if you have the following data set: 2, 5, 8, 9, 12, the mean would be calculated as follows:(2 + 5 + 8 + 9 + 12) ÷ 5 = 7.2 . So the mean of this data set is 7.2. The mean is a useful measure of central tendency because it takes into account all the values in the data set and provides a single representative value that can be used to describe the overall characteristics of the data.

given

For a population receiving pharmacological treatments, the mean wake time was estimated with a 95% confidence interval.

where t/2 is the crucial value from the t-distribution with n-1 degrees of freedom and a confidence level of 95%, and x is the sample mean, s is the sample standard deviation, n is the sample size.

When we enter the provided values, we obtain:

s = 23.3

n = 23

t0.025,22 = 2.074

The mean wake time estimate with a 95% confidence interval for a population receiving medication is thus:

82.1 ± 2.074 * (23.3/√23)

which is equivalent to:

(71.4, 92.8)

The absence of the value 105.0 from the interval shows that the medication therapy significantly reduces wake time.

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The solution set for the inequality is x < -10

The different signs for representing inequalities are;

From the information given, we have that;

−4x−38<2

To solve for the value of x, take the steps;

collect the like terms

-4x> 2 + 38

Add the values

-4x> 40

Divide both sides by the coefficient of x, we have;

x > -10

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Thus, the solution set for the cost of each notebook that can be bought by George is:  (0 ≤ x ≤ 6).

A linear equation is a one-variable equation of the a straight line. The variable only has one power, which is 1. Simple algebraic operations are used to solve linear equations in one variable, which can have the form ax+b=0.

Given that:

So, the linear equation follows

Amount for 4 notebooks + Left amount  = total amount

4*x + 12 ≤ 36

4x ≤ 36 - 12

4x ≤ 24

x ≤ 24/4

x ≤ 6

So, (0 ≤ x ≤ 6)

Thus, the solution set for the cost of each notebook that can be bought by George is:  (0 ≤ x ≤ 6).

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The area of the training field that has the shape of a rectangle and two semicircle would be = 9,755.46m²

To calculate the area of the training field, the area of the rectangle and the two semicircles should be determined and added together.

The area of rectangle = length×width

where:

length = 96m

width = 66m

area of rectangle = 66×96 = 6,336m²

Area of the two semicircle = Area of a circle = πr²

radius = diameter/2 = 66/2 = 33m

area of a circle= 3.14×33×33 = 3419.46m²

Therefore the area of the training field = 6,336m²+3419.46m² = 9,755.46m²

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