The regression lines 3x+2y=26 and 6x+y=31 are linear regressions
The mean values are 4 and 7 and the correlation coefficient between x and y is 0.25
The standard deviation of x is 2/13
The mean value and the correlation
We have the equations to be:
3x+2y=26 and 6x+y=31
Make y the subject in the second equation
y = 31 - 6x
Substitute y = 31 - 6x in the first equation
3x+2[31 - 6x] = 26
Expand
3x+ 62 - 12x = 26
Collect like terms
3x - 12x = 26 - 62
Evaluate
-9x = -36
Divide by - 9
x = 4
Substitute x = 4 in y = 31 - 6x
y = 31 - 6 * 4
y = 7
This means that the mean values are 4 and 7
To determine the correlation coefficient, we make y the subject in 3x+2y=26 and x the subject in 6x+y=31.
So, we have:
y = 13 - 3x/2 and x = 31/6 - 1/6y
The above means that:
Bxy = -1/6 and Byx = -3/2
The correlation coefficient is then calculated as:
r^2 = Bxy * Byx
r = -1/6 * -3/2
r = 0.25
Hence, the correlation coefficient between x and y is 0.25
The standard deviation of x
We have:
Var(y) = 4
In (a), we have:
y = 13 - 3x/2
To solve further, we make use of:
Var(y) = Var(ax + b) = a^2Var(x)
This gives
Var(y) = Var(13 - 3x/2) = 13^2 * Var(x)
So, we have:
Var(y) = 13^2 * Var(x)
Substitute 4 for Var(y)
4 = 13^2 * Var(x)
Divide both sides by 13^2
4/13^2 = Var(x)
Express 4 as 2^2
(2/13)^2 = Var(x)
So, we have:
Var(x) = (2/13)^2
Take the square root of both sides
SD(x) = 2/13
Hence, the standard deviation of x is 2/13
Name the property that justifies the statment If AB - BC = 12, then AB = 12 + BC.
The property that justifies the statement is the commutative law of addition
Commutative law of additionThis law occurs if the same number or constant is added to both sides of an equation.
Given the equation
AB - BC = 12
Add BC to both sides
AB - BC + BC = 12 + Bc
AB = 12 + BC
Hence the property that justifies the statement is the commutative law of addition
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If f(x) = 5x - 1, then f-1 (x)
Step-by-step explanation:
[tex]f(x) = 5x - 1[/tex]
[tex] \: [/tex]
[tex]y = 5x - 1[/tex]
[tex]5y - 1 = x[/tex]
[tex]5y = x + 1[/tex]
[tex]y = \frac{x + 1}{5} [/tex]
[tex] {f}^{ - 1} (x) = \frac{x + 1}{5} [/tex]
Given functions f ( x ) = 1 √ x and m ( x ) = x 2 − 4 , state the domains of the following functions using interval notation.
Domain of f ( x ) /m ( x ):
Domain of f ( m ( x ) ):
Domain of m(f(x)):
The domain of a function f(x)/m(x) = 1/√x(x² - 4) is (0, ∞) - {0, 2, -2} for other function is shown in the solution.
What is a function?It is defined as a special type of relationship, and they have a predefined domain and range according to the function every value in the domain is related to exactly one value in the range.
We have:
f(x) = 1/√x
m(x) = x² - 4
Domain of f(x)/m(x):
f(x)/m(x) = (1/√x)/(x² - 4)
f(x)/m(x) = 1/√x(x² - 4)
The denominator cannot be zero:
√x(x² - 4) ≠ 0
x(x - 2)(x+2) ≠ 0
x ≠ 0, 2, -2
and x > 0
Domain of f(x)/m(x) is: (0, ∞) - {0, 2, -2} or [tex]\:\left(0,\:2\right)\cup \left(2,\:\infty \:\right)[/tex]
Domain of f(m(x)):
f(m(x)) = 1/√(x² - 4)
x² - 4 > 0
Domain: [tex]\rm \left(-\infty \:,\:-2\right)\cup \left(2,\:\infty \:\right)[/tex]
Domain of m(f(x)):
= ((1/√x)² - 4)
Domain: [tex]\:\left(0,\:\infty \:\right)[/tex]
Thus, the domain of a function f(x)/m(x) = 1/√x(x² - 4) is (0, ∞) - {0, 2, -2} for other function is shown in the solution.
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what is 4³ writ
ten in expanded form?
Answer:
4^3 written in expanded form is 4*4*4
Mark as Brainliest please
Answer: 64
Step-by-step explanation:
Hii!
Do you need to know what 4^3 written in expanded form is? No problem!
4^3=4*4*4 (the ^3 tells us to multiply the base (which is 4 here) times 3)
The answer is 64.
Hope that this helped! Best wishes.
--
What are the solution(s) to the quadratic equation x² - 25 = 0?
h
O x=5 and x =
-5
−5
x = 25 and x = -25
x = 125 and x = -125
Ono real solution’s
Answer:
x = ±5
Step-by-step explanation:
x² - 25 = 0
x² = 25
√x² = √25
x = ±5
Check:
5² - 25 = 0
-5² - 25 = 0
25 - 25 = 0
A quadrilateral has vertices E(–4, 2), F(4, 7), G(8, 1), and H(0, –4). Which statements are true? Check all that apply.
A) The slope of EH is -8/5
B) The slopes of EF and GH are both 5/8
C) FG is perpendicular to GH.
D) Quadrilateral EFGH is a parallelogram because both pairs of opposite sides are parallel.
E) Quadrilateral EFGH is a rectangle because all angles are right angles.
Answer:
D) Quadrilateral EFGH is a parallelogram because both pairs of opposite sides are parallel.
B) The slopes of EF and GH are both 5/8
Step-by-step explanation:
The following inference can be made about each answer choices:
For option A
A) The slope of EH is 3/2 and not -8/5
For EH, slope = (2--4)/(0--4) = 6/4 =3/2
For option B
B) The slopes of EF and GH are both 5/8
slope of a graph can be determined by change in y axis/ change in x axis
For EF, slope = (7-2)/(4--4) = 5/8
for GH, slope = (1--4)/(8-0) = 5/8
For option C
C) FG is perpendicular to GH, its can't be determined since it is concluded that the quadrilateral is a parallelogram, therefore this option is wrong.
For option D
D) Quadrilateral EFGH is a parallelogram because both pairs of opposite sides are parallel.
Slope of a graph can be determined by rise divided by run change in y axis/ change in x axis
For EF, slope = (7-2)/(4--4) = 5/8
for GH, slope = (1--4)/(8-0) = 5/8
For EH, slope = (2--4)/(0--4) = 6/4 =3/2
for FG, slope = (7-1)/(8-4) = 6/4 =3/2
EF and GH give the same slope, likewise EH and FG and they are opposite to each other, this make them parallel. Therefore, EFGH is a parallelogram.
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Drag each number to a box on the right to match each expression on the left with its product.
0.832 added to
Expression Product
83.2 × 0.1
832
8.32 × 102
8.32
83.2 × 102
8,320
832 × 0.001
0.832
The match has done below:
What is expression?An expression is a set of terms combined using the operations +, – , x or , /.
83.2*0.1= 8.32
8.32 × 102=848.64
83.2*102=8486.4
832 × 0.001=0.832
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82% of what number is 94.3
Answer:
let the no. be X
82% of X = 94.3
82/100 *X = 94.2
X = 94.2 *100/82
X = 94.2/0.82
X = 114.8
Answer:
115
Step-by-step explanation:
82% = 82/10 = 0.82
94.3 / 0.82 = 115
Hope this helps
PLEASE HELP!!
Discussion Topic
Earlier in this course, you explored Euclidean geometry, which is the study of flat space. This
approach follows the teachings of Euclid, in which he describes the relationships between
points, lines, and planes without any numerical measurement. You saw evidence of Euclidean
geometry inside several proofs and geometric constructions.
In contrast, the focus of this unit is understanding geometry using positions of points in a
Cartesian coordinate system. The study of the relationship between algebra and geometry was
pioneered by the French mathematician and philosopher René Descartes. In fact, the
Cartesian coordinate system is named after him. The study of geometry that uses coordinates
in this manner is called analytical geometry.
It's clear that this course teaches a combination of analytical and Euclidean geometry. Based
on your experiences so far, which approach to geometry do you prefer? Why? Which
approach is easier to extend beyond two dimensions? What are some situations in which one
approach to geometry would prove more beneficial Han the other? Describe the situation
and why you think analytical or Euclidean geometry is more applicable.
Based on my experiences so far, the approach to geometry that I prefer is: Euclidean Geometry. This is because the problems are easy to visualize since they are restricted to two-dimensional planes.
Which approach is easier to extend beyond two dimensions?The approach that is easier to extend beyond two dimensions is Euclidean Geometry. Again, this is because of how it deals with shapes and visualization of the same.
Take for instance a triangle; it is easy to go from a two-dimensional equilateral triangle to a square pyramid.
What are some situations in which one approach to geometry would prove more beneficial than the other?Analytical geometry is a superior technique for discovering objects (points, curves, and planes) based on their qualities in some situations than Euclidean geometry is in others (for example, when employing topography or building charts).
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What does the ratio 4: 18 represent in this situation?
Answer:
2:9 or 2/9
Step-by-step explanation:
I guess this question asks the simplest form of ratio 4:18
so I divided it by two and since they cannot be divided further that's the answer
you can either choose to write it in ratio form or fraction form that's your choice good day.
Please helpppp!!!!!!!!!!
The vertex form of the quadratic function f(x) = x² + 2x + 3 is given as follows:
f(x) = (x + 1)² + 2
What is the equation of a parabola given it’s vertex?The equation of a quadratic function, of vertex (h,k), is given by:
y = a(x - h)² + k
In which a is the leading coefficient.
In this problem, the function is:
f(x) = x² + 2x + 3
Completing the squares, we find the equation in vertex form, as follows:
f(x) = (x + 1)² + 2
As (x + 1)² = x² + 2x + 1, hence 2 has to be added to find the equivalent function.
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QUESTION 8 - 1 POINT
The median monthly rent in 1994 was $499 and $633 in 2001. What was the percent increase in the
median monthly rent prices from 1994 to 2001? Round to the nearest tenth of a percent.
Answer:
26.85%
Step-by-step explanation:
first you find the difference in price increase
633-499=134
*percentage increase=increase value/original value x100
so;=134/499x100=28.85%
hope it helps you.please don't forget to give me a thanks
If the sides of a square are increased by 2 inches, the area becomes 25 squares inches. Find the length of sides of the original square.
You know that the sides of a square are increased by 2 inches: the expression should be written as (x+2)
The area is 25 square inches
The area of a square is s×s or s²
so it can be solved as:
(x+2)²=25
[tex](\sqrt{x+2})^{2} =\sqrt{25}[/tex]
x+2=5
x=3
The length of the original side is 3 inches
Hope it helps!
Write an equation in point-slope form of the line that passes through the given point and with the given slope m
(-9,2); m=6
The equation is [tex]\boxed{y-2=6(x+9)}[/tex].
Write the ratio as a fraction in lowest terms.
Compare in inches.
4 feet to 49 inches
Answer:
48/49
Step-by-step explanation:
divison and multiplcation
The graphs of three functions are shown. Which statements accurately compare the functions on the graph? Select two options. The square root and quadratic function share a y-intercept. The square root and absolute value function share an x-intercept. The range of the square root and quadratic function are the same. The range of the square root and absolute value function are the same. The quadratic function and the absolute value function have a minimum while the square root function has a maximum.
The following statements accurately compare the three functions on the graph: option A and C.
How to interpret the graph?In Geometry, the following statements are true about the graph of a function:
The x-intercepts of two or more functions are the same when their curves meet the x-axis at the same point. The y-intercepts of two or more functions are the same when their curves meet the y-axis at the same point. The ranges of two or more functions are the same when they all have the same vertical extension. The absolute value function and square root function both have the same minimum i.e at lower end of their range.By critically observing the graph of a function, we can logically deduce that the following statements accurately compare the three functions on the graph:
"The square root and quadratic function share a y-intercept.""The range of the square root and absolute value function are the same."Read more on function here: brainly.com/question/4246058
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Quadratic Functions graph
Answer:
y=-x^2-4x-1
Step-by-step explanation:
when it is an arch like an upside down U then its
-x^2
it passes through the y axis at -1
its vertex or high point is -2,3 so its
-4x
Answer:
See below
Step-by-step explanation:
Dome shaped parabola so 'a' is negative
'c' is determined where x = 0
this value is -1
Axis of symmetry is the x value of the vertex (which is the high point of the dome)
x = -2
Use a calculator to graph the functions y=-3x-21 and y=x³-3x-3. How many points of intersection do the
functions share?
0
1
2
3
Answer:
1
Step-by-step explanation:
When you graph the functions they intersect at one point
(-3.368119, -31.10436)
What is the equation of the line that has a slope of -4 and passes through the point (2,3)?
Answer:
The answer is y = -4x+11
what is the area of a triangle (-4,-5),(3,-3),(3,-7)?
i will give brainliest please help quick
The area of a triangle with vertices (-4,-5), (3,-3), and (3,-7) will be 7 square units.
What is the area of the triangle?The vertices of the triangle are (x₁, y₁), (x₂, y₂), and (x₃, y₃).
Then the area of the triangle will be
Area = 1/2 |[(x₁y₂ + x₂y₃ + x₃y₁) - (y₁x₂ + y₂x₃ + y₃x₁)]|
We have
(x₁, y₁) ⇒ (-4, -5)
(x₂, y₂) ⇒ (3, -3)
(x₃, y₃) ⇒ (3, -7)
Then the area will be
Area = 1/2[{(-4) x (-3) + (3) x (-7) + (3) x (-5)} – {(-5) x (3) + (-3) x (3) + (-7) x (-4)}]
Area = 1/2 [(12 – 9 – 21) – (- 15 – 9 + 28)]
Area = 1/2[-18 + 4]
Area = 1/2 × 14
Area = 7 square units
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A doctor's office schedules appointments in 30-minute time slots. All appointments are 30 minutes long. The office is open 8 hours per day, 5 days a week. How many appointments can they schedule, in total, for Thursday and Friday?
Need help!!!!!!!!!!!!!!!!!
Terry wants to pour cement around the edge of the circular patio in her backyard.The patio has a radius of 5 feet.What is the distance,in feet,around the edge of the patio?Use 3.14 for Pi.PLEASE EXPLAIN
E.15.7
F.31.4
G.49.3
H.78.5
Answer:
F. 31.4 ft
Step-by-step explanation:
The distance around the edge of a circle is called the circumference.
Formula for the circumference of a circle
[tex]\sf Circumference\:of\:a\:circle=2 \pi r[/tex]
(where r is the radius)
Given values:
radius = 5 ftπ = 3.14Substitute the given values into the formula:
[tex]\begin{aligned}\implies \sf circumference & = \sf 2 \cdot 3.14 \cdot 5\\ & = \sf 31.4\:ft \end{aligned}[/tex]
Therefore, the distance around the edge of the circular patio is 31.4 ft.
The distance around the edge of the patio is 31.4 feet, which is determined by the circumference of a circle. The correct answer is option (F).
To find the distance around the edge of the circular patio, we need to calculate the circumference of the circle.
The formula for the circumference of a circle is given by:
Circumference = 2 × π × radius
Given that the radius of the patio is 5 feet and using the approximate value of π as 3.14, we can now calculate the circumference:
Circumference = 2 × 3.14 × 5
Circumference = 31.4 feet
Therefore, the distance around the edge of the patio is 31.4 feet.
Hence, the correct answer is option (F).
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Which of the following statements must be true about this diagram? Check
all that apply.
A. mz2+ mz3 = mz4
B. mz1+ m2 2 = m/3
C. m23 is greater than m<2
D. m24 is greater than mz1
E. mz1+mz2 = mz4
F. mz4 is greater than m<2
Answer:
D, E, F is the answer.
Step-by-step explanation:
From the diagram:-
m∠ 4 is greater than m∠ 1m∠ 4 is greater than m∠ 2m∠ 1 + m∠ 2 = m∠ 4Therefore, D, E, F.
-------------------------------
Tim go to school.His age is a cube number.His age is double 1 square number and half a different square number.How old is Tim?
Answer:
Tim is 8 years old.
Explanation:
8 is the cube number of 2, as 2 × 2 × 2 = 8. Additionally, 8 is double 4, which is the square number of 2, and half of 16, which is the square number of 4.
Tim who goes to school is 8 years old.
Why numerical ability is important ?Good numerical ability describes your ability to think and conclude logical thoughts in your daily life also in your working role how you handle data in form of numbers, graphs, statements etc.
According to the given question Tim goes to school.
His age is a cube number let that number be x therefore age of Tim would be x³.
His age can also be defined as double of 1 square number which is 2x² and half of a different square of a numbers.
Let us equate x³ = 2x² and by hit and trial we get to know that x = 2 satisfies this condition.
So, Age of Tim could be 8 years,Now lets check our third statement half a different square number 16 is square of 4 so half of 16 is also 8.
Thus Tim is 8 years old.
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A chord AB divides a circle of radius 8 cm into two segments. If AB subtends a
central angle of 45, find the area of the minor segment.
Answer:
Area of the minor segment = 2.505324230749 cm²
Step-by-step explanation:
Area of the minor segment
= Area of the sector ABC - Area of the triangle ABC
……………………………………………………………………………………
• Area of the sector ABC
= Area of the whole circle ÷ 8
= (π×8²) ÷ 8
= 8π
______
•• Area of the triangle ABC
= (1÷2) × CA × CB × sin(45)
= (1÷2) × 8 × 8 × (√2/2)
= 16√2
______
Thus
Area of the minor segment
= 8π - 16√2
= 2.505324230749
How many Identities are there in algebra?
Name them.
Answer:
the technical number depends on what you are including to be algebraic identities.
There are multiple forms of most identities (pos. / neg. and multiple ways of writing the same identity)
generally, you can consider there to be 10
Step-by-step explanation:
algebraic identity: an equality that holds true for any variable values
standard identities:
square of binomial:
(a+b)² = a² +2ab + b²
(a - b)² = a² - 2ab + b²
difference of squares:
(a + b)(a - b) = a² - b²
----
product of two binomials:
(x + a)(x + b) = x² + (a + b)x + ab
square of trinomial:
(x + y + z)² = x² + y² + z² + 2xy + 2yz + 2zx
(x - y - z)² = x² + y² + z² -2(xy + yz - zx)
cube of binomial:
(x + y)³ = x³ + y³ + 3xy (x + y)
(x - y)³ = x³ + y³ - 3xy (x - y)
(a - b)³ = a³ - 3a²b + 3ab² - b³
sum of cubes:
a³ + b³ = (a + b)(a² - ab + b²)
x³ + y³ = (x + y)(x² - xy + y²)
x³ + y³ = (x - y)(x² + xy + y²)
difference of cubes:
a³ - b³ = (a - b)(a² + ab + b²)
x³ - y³ = (x - y)³ + 3xy(x - y)
--
x³ + y³ + z³ - 3xyz = (x + y + z)(x² + y² + z² - xy - yz - zx)
= 1/2 (x + y + z) [(x -y)² + (y - z)² + (z - x)²]
(a + b + c)³ = a³ + b³ + c³ + 3(a + b)(b + c)(c + a)
--
and
if x + y + z = 0, then x³ + y³ + z³ = 3xyz
hope this helps!!
(this took me a while to write; there are also a few complicated identities also that I've left out)
[tex]( {a + b})^{2} = {a}^{2} + {b}^{2} + 2ab \\ \\ {(a - b)}^{2} = {a}^{2} + {b}^{2} - 2ab \\ \\ {a}^{2} - {b}^{2} = (a + b)(a - b) \\ \\ {a + b + c}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2ab + 2bc + 2ca \\ \\ {a + b}^{3} = {a}^{3} + {b}^{3} + 3ab(a + b) \\ \\ {a - b}^{3} = {a}^{3} - {b}^{3} - 3ab(a - b) \\ \\ {a}^{3} + {b}^{3} + {c}^{3} - 3abc = (a + b + c)( {a}^{2} + {b}^{2} + {c}^{2} - ab - bc - ca).[/tex]
Consider the given density curve.
A density curve is at y = one-third and goes from 3 to 6.
What is the value of the median?
3
4
4.5
6
Picture posted below
Answer: 4.5
Step-by-step explanation:
[tex]\frac{6+3}{2}=\boxed{4.5}[/tex]
We want to find the median for the given density curve.
The value of the median is 4.5. ({3+6)/2}
Let's see how to solve this.
First, for a regular set {x₁, ..., xₙ} we define the median as the middle value.
The difference between a set and a density curve is that the density curve is continuous, so getting the exact middle value can be harder.
Here, we have a constant density curve that goes from 3 to 6.
Because it is constant, the median will just be equal to the mean, thus the median is the average between the two extreme values.
Remember that the average between two numbers a and b is given by:(a + b)/2
So we get: m = (6 + 3)/2 = 4.5
So we can conclude that the value of the median is 4.5, so the correct option is the second one, counting from the top.
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Henry knows that the circumstance of a circle is 18pi inches. What is the area of the circle?
a. 36pi in²
b. 81pi in²
c. 162pi in²
d. 324pi in²
-------------------------------------------------------------------------------------------------------------
Answer: [tex]\textsf{Option B, 81}\pi\textsf{ in}^2[/tex]
-------------------------------------------------------------------------------------------------------------
Given: [tex]\textsf{Circumference = 18}\pi[/tex]
Find: [tex]\textsf{The area of the circle}[/tex]
Solution: We need to first determine the radius using the circumference formula and once we get the radius then we can plug in the value into the area formula and get our final answer.
Determine the radius
[tex]c = 2 \pi * r[/tex][tex]18\pi = 2 \pi * r[/tex][tex]\frac{18\pi}{2\pi} = \frac{2 \pi}{2\pi} * r[/tex][tex]\frac{18\pi}{2\pi} = r[/tex][tex]9 = r[/tex]Determine the area
[tex]A = \pi * r^2[/tex][tex]A = \pi * (9)^2[/tex][tex]A = \pi * (9 * 9)[/tex][tex]A = 81\pi[/tex]Therefore, the correct answer would be option B, 81π in2.
What is the value of n in the equation 2n² + 4n = 0? What is the value of n in the equation 2n² + 4n = 0 ?
N = 0
2(0)² + 4(0) = 0
0 + 0 = 0
