The sampling method used in this case is random sampling and the sample is representative.
What is a sample and what makes a sample to be representative?A sample is a small proportion of individuals taken from the general population to be studied. For a sample to be representative it is expected that all the individuals represent the population, for example, if the population includes people of different ages the sample should include this too.
Is the sample representative?The random sample selected is representative because the seats of the students selected are distributed within the class rather than in only one row or line.
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If an item that originally cost $18 is decreased to $12, what is the percentage of decrease in the item?
convert the system to an augmented matrix. type each element of the answer in the spaces provided. 2x y
The augmented matrix of the solution to the system of equations is x = 4 and y = -1/2.
The augmented matrix of the system of equations 2x + y = 8 and 3x - y = 7 can be written as follows:
|2x + y = 8 |
|3x - y = 7 |
This can be rewritten in matrix form as:
|2 1 | |x | | 8 |
|3 -1| |y | | 7 |
To solve this system of linear equations, we can use the Gauss-Jordan elimination method. First, we add the first row to the second row to eliminate the x coefficient from the second equation:
|2 1 | |x | | 8 |
|0 -2| |y | | 1 |
Then, we can divide the second row by -2 to get the coefficient of y to be 1:
|2 1 | |x | | 8 |
|0 1 | |y | |-1/2|
Finally, we can subtract the second row from the first row to eliminate the y coefficient from the first equation:
|2 0 | |x | | 8/2|
|0 1 | |y | |-1/2|
Therefore, the solution to the system of equations is x = 4 and y = -1/2.
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Find f(-5) if f(x) = |x + 1|
Answers are 4, 5, or 6
Answer:
f(-5) = 4
Step-by-step explanation:
[tex]f(x)=|x+1|\\f(-5)=|-5+1|=|-4|=4[/tex]
–35 –
–20 = N please need k to
Answer: - 15 = N
Step-by-step explanation:
2 negatives make a positive so it would be -35 + 20 = -15 Have a nice day ;)
The monthly cost (in dollars) of a long-distance phone plan is a linear function of the total calling time (in minutes). The monthly cost for 52 minutes of calls is $14.06 and the monthly cost for 78 minutes is $17.18. What is the monthly cost for 73 minutes of calls?
Answer:
16.58
Step-by-step explanation:
as you can see from the graph, there's a monthly fixed cost on Y axis. so you need to figure out 1: how much per minute. and 2. the monthly fixed fee. you've got 2 scenarios = 2 equations, for 2 variables. so you can solve both.
assume: x=per min rate; m = monthly fixed cost.
1. 14.06 =52x+m
2. 17.18 =78x+m
use equation 2 minus equation 1 & you get
3.12 = 26 x. so x = 0.12
plug this into equation 1: 14.06 =52*0.12 +m so m=7.82
now for 73 mins the cost = 73*0.12 +7.82 =16.58
A liter of petrol cost 93 for an equation to find the cost in pound of any number of liter of petrol
The equation for finding cost y for x liters of petrol is y = 93x
What is an equation?An equation is a mathematical statement that shows that two mathematical expressions are equal.
Given that, A liter of petrol cost £93,
Since, the unit rate of the petrol is £93 per liter
If we say let x be the number of liters we need, the total cost will have to pay will be = 93x
And, if total cost is y, then,
y = 93x
Hence, the equation for finding cost y for x liters of petrol is y = 93x
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Claire is 5 feet tall and casts a 96 inch shadow. How tall is her friend Steve if his shadow is 1.5 inches shorter than hers?
Answer:
4.725 ft
Step-by-step explanation:
well if i see this right the shadow for claire is 1.60x the person's hight
Sophie is a dog that loves to play catch. Unfortunately, she isn't very good, and the probability that she catches a ball is only 0.2. Let x be the number of tosses required until Sophie catches a ball. (a) Does x have a binomial or a geometric distribution? (b) What is the probability that it will take exactly two tosses for Sophie to catch a ball? P(exactly two tosses) (c) What is the probability that more than three tosses will be required? P(more than three tosses)
X has a geometric distribution because it is the number of trials (tosses) required until a success (catching the ball) occurs.
b) The probability that it will take exactly two tosses for Sophie to catch a ball is P(x=2) = (0.2)(0.8)^1 = 0.16. This is calculated by multiplying the probability of success (0.2) by the probability of failure (0.8) raised to the power of the number of trials (2-1=1)
c) To find the probability that more than three tosses will be required, we need to find the probability that Sophie does not catch the ball on the first three tosses and then catch it on the fourth toss.
This can be found by summing the probabilities of Sophie not catching the ball on the first three tosses (0.8^3 = 0.512) and Sophie catching the ball on the fourth toss (0.8^3*0.2 = 0.1024). The probability that more than three tosses will be required is P(x>3) = 1 - P(x≤3) = 1 - (0.512 + 0.1024) = 0.3856.
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4. For a process quality characteristics, the specification limits are 0.4037 +/- 0.0013 (that is from 0.4024 to 0.4050). The following data gives the data for 14 measurement data sets, each data set is a subgroup of 5 measurement. The value is recorded in the units of 0.0001 (that is, the specification limit will be considered 24 to 50) Based on the following data, compute Cp,Cpk,Pp and Ppk.(Use MINITAB is ok) and determine if the capability of the process. Subgroup Subgroup # 1 2 3 4 5 # 1 2 3 4 5 . 1 36 35 34 33 32 34 28 35 34 38 . 2 31 31 34 32 30 36 35 37 34 33 . 3 30 30 32 30 32 30 37 33 34 35 . 4 32 33 33 32 35 38 31 33 33 33 . 5 32 34 37 37 35 33 30 34 33 35
If the calculated Cp and Cpk values are greater than 1, the process is considered capable. If Pp and Ppk are greater than 1, the process is considered capable.
To calculate Cp, Cpk, Pp, and Ppk using MINITAB, you would need to input the data into the software and run the appropriate statistical analysis.
Cp and Cpk are measures of a process's capability, they are calculated as follows:
Cp = (USL - LSL) / (6*σ)Cpk = min(Cpu, Cpl)Where,
USL and LSL are the upper and lower specification limitsσ is the standard deviation of the process.Pp and Ppk are similar to Cp and Cpk, but they are calculated using the range of the data instead of the standard deviation.
Pp = (USL - LSL) / (4*R)Ppk = min(Ppu, Ppl)Where R is the range of the data.
If the calculated Cp and Cpk values are greater than 1, the process is considered capable. If Pp and Ppk are greater than 1, the process is considered capable.
It is worth noting that Capability analysis can only be performed on stable and in-control processes. If the process is not in control, analyzing process capability is not meaningful.
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2 x – 3 y = 7
–4 x + y = –5
What is the x -value of the solution to this system of equations?
Answer:
x = [tex]\frac{4}{5}[/tex]
Step-by-step explanation:
2x - 3y = 7 → (1)
- 4x + y = - 5 → (2)
multiplying (2) by 3 and adding to (1) will eliminate y
- 12x + 3y = - 15 → (3)
add (1) and (3) term by term to eliminate y
- 10x + 0 = - 8
- 10x = - 8 ( divide both sides by - 10 )
x = [tex]\frac{-8}{-10}[/tex] = [tex]\frac{4}{5}[/tex] (= 0.8 )
Add 4x +1
To
5x+6
Write the following as an algebraic expression. Simply if possible
Answer:
9x + 7
Step-by-step explanation:
Add 4x + 1 to 5x + 6
in an algebraic expression is:
4x + 1 + 5x + 6
To simplify, combine like terms. This means add the x terms together and add the constants (plain number- - the 1 and 6) together.
4x + 1 + 5x + 6
= 4x + 5x + 1 + 6
= 9x + 7
scenario 3-6 a researcher wishes to study how the average weight y (in kilograms) of children changes during the first year of life. he plots these averages versus the age x (in months) and decides to fit a least-squares regression line to the data with x as the explanatory variable and y as the response variable. he computes the following quantities. r
The slope of the least-squares line is: 0.30
The correct answer is an option (A)
We have following information:
correlation between X and Y (r) = 0.9
mean of the values of X ([tex]\bar{X}[/tex]) = 6.5
mean of the values of Y ([tex]\bar{Y}[/tex]) = 6.6
the standard deviation of the values of X ([tex]S_{X}[/tex]) = 3.6
the standard deviation of the values of Y ([tex]S_{Y}[/tex]) = 1.2
We know that the slope of a least squares regression can be calculated by the formula,
slope m = r [tex]\frac{S_\bar{Y}}{S_\bar{X}}[/tex],
where, r is the correlation coefficient
Let us assume that for given scenario, m represents the slope of of the least-squares line.
Using above formula,
⇒ m = r [tex]\frac{S_\bar{Y}}{S_\bar{X}}[/tex]
⇒ m = 0.9 × [tex]\frac{1.2}{3.6}[/tex]
⇒ m = 0.9 × 0.333
⇒ m = 0.2997
⇒ m ≈ 0.3
Thus, the slope is 0.30
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The complete question is:
A researcher wishes to study how the average weight Y (in kilograms) of children changes during the first year of life. He plots these averages versus the age X (in months) and decides to fit a least- squares regression line to the data with X as the explanatory variable and Y as the response variable. He computes the following quantities.
r = correlation between X and Y = 0.9
X = mean of the values of X = 6.5
Y = mean of the values of Y = 6.6
S_(X) = standard deviation of the values of X = 3.6
S_(Y) = standard deviation of the values of Y = 1.2
The slope of the least-squares line is: ?
A. 0.30 B. 0.88 C. 1.01 D. 2.70 E. 3.00
Write an expression for a polynomial function whose graph intercepts the horizontal axis at -7,8 and 15
The polynomial function with the given intercepts of the hirzontal axis can be written as:
p(x) = (x + 7)*(x - 8)*(x - 15)
How to write the polynomial?We know that a polynomial of degree N whose leading coefficient is 1 and has the zeros {x₁, x₂, ...}
Then the polynomial can be written as:
p(x) = (x - x₁)*(x - x₂)*...
Here the zeros (also called intercepts of the horizontal axis, like on this case) are {-7, 8, 15}
Then wecan write the polynomial with these zeros as:
p(x) = (x - (-7))*(x - 8)*(x - 15)
p(x) = (x + 7)*(x - 8)*(x - 15)
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PLEASE HELP ASAP!!!
Mrs. Lopez needs 40 ounces of sweetened milk to make flans. She has 24 ounces. Which equation shows how many more ounces of sweetened milk Mrs. Lopez needs to make flans?
Answer: As Mrs Lopez required 40 ounce
Step-by-step explanation:
PLEASE HELP ME IT’S URGENT
The images of the points after the transformation are (6, 1), (3, 6), (5, 2) and (-8, -4)
How to determine the coordinates of the point?r(x-axis) o T(2, -3) (4, 2)
This implies that we reflect the point (4, 2) across the x-axis and then translate it by (x + 2, y - 3)
Mathematically, this is represented as
Image = (x + 2, 3 - y)
Substitute the known values in the above equation, so, we have the following representation
Image = (4 + 2, 3 - 2)
Evaluate
Image = (6, 1)
T(2, -5) o R 90 CCW (4, 2)
This implies that we translate the point (4, 2) by (x + 2, y - 5) and then rotate it by 90 degrees counterclockwise
Mathematically, this is represented as
Image = (5 - y, x + 2)
Substitute the known values in the above equation, so, we have the following representation
Image = (5 - 2, 4 + 2)
Evaluate
Image = (3, 6)
T(1, 4) o r(y-axis) (4, 2)
This implies that we translate the point (4, 2) by (x + 1, y + 4) and then reflect it across the y-axis
Mathematically, this is represented as
Image = (x + 1, 4 - y)
Substitute the known values in the above equation, so, we have the following representation
Image = (4 + 1, 4 - 2)
Evaluate
Image = (5, 2)
r(y-axis) o T(1, 4) (4, 2)
This implies that we reflect the point (4, 2) across the y-axis and then translate it by (x + 4, y + 2)
Mathematically, this is represented as
Image = (-x - 4, y + 2)
Substitute the known values in the above equation, so, we have the following representation
Image = (- 4 - 4, 2 + 2)
Evaluate
Image = (-8, 4)
Hence, the image is (-8, -4)
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What is the solution to this equation: 42 +82=²? (Round answer to the nearest tenth.)
O c= 8.9
O e = 12
Oc=6.3
O c=3.5
The solution to this equation: 42 +82=x² is x = 12.
What is square number?A square number, also known as a perfect square, is an integer that is the square of another integer; in other words, it is the result of multiplying another integer by itself. For instance, 9 is a square number because it equals 32 and can be written as 3 3.
Instead of the product n n, the equivalent exponentiation n2, which is typically pronounced "n squared," is used to represent a number's square. The name of the shape is where the term "square number" originated. The area of a unit square (1 × 1) is the unit of area.
The solution to this equation: 42 +82=x²
x = √(42 +82)
x = √(144)
x = 12
Thus, The solution to this equation: 42 +82=x² is x = 12.
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What is the slope of the following linear graph 2/3 -2/3 3/2 -3/2
The slope of following points (3, 3) and (6,1) is -2/3 .
What is Linear equation ?
Linear equation can be defined as the equation in which the highest degree is one.
Given points are (3, 3) and (6,1)
we know that slope = y2-y1 / x2-x1
y2-y1 = 1-3
The difference of y -intercept is -2
= -2
x2-x1 = 6-(3)
= 6-3
The difference of x-intercept is 3
= 3
So, slope could be y2-y1 / x2-x1 that is -2/3.
Therefore, The slope of following points (3, 3) and (6,1) is -2/3 .
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Will Mark brainliest
Write an equation in point slope form for the line that passes through the given point and is perpendicular to the graph of each equation.
(3, - 2) ; y = 2/3x + 4
An equation in point slope form for the line that passes through the given point and is perpendicular to the graph of each equation is y=2/3 x²+4x
How to find the equation?A mathematical equation is a formula that uses the equals sign ('=') to express the equality of two expressions. The meanings of the word equation and its cognates in other languages can vary slightly. For instance, an equation in English is any well-formed formula consisting of two expressions related by an equals sign, while an equation in French is defined as containing one or more variables.
step 1
y=2/3+4
y=2/3 x²+4x
y=m x+ b
step 2
y= y coordinate
m=slope
x=x coordinate
b=y intercept
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Solve the system by elimination 8x+3y=4 2x+y=2 what is the solution
The solution for the system of equations 8x + 3y = 4 and 2x + y = 2 by elimination are x = -1, y = 4
How to evaluate for the solutions of the equations by eliminationwe shall write the equations as:
8x + 3y = 4...(1)
2x + y = 2...(2)
multiply equation (2) by 3 to get equation (3)
3(2x + y) = 3 × 2
6x + 3y = 6...(3)
subtract equation (1) from (3) to eliminate y
6x + 3y - 8x - 3y = 6 - 4
-2x = 2
divide through by -2
x = -1
put the value -1 for x in equation (2) to get y
2(-1) + y = 2
-2 + y = 2
y = 2 + 2 {add 2 to both sides}
y = 4
Therefore, the solution for the system of equations 8x + 3y = 4 and 2x + y = 2 by elimination are x = -1, y = 4.
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Label The Missing angle measures for this triangle.
The measure of the missing angles are 100° and 30°
What is a triangle?A polygon with three vertices, angles and sides.
Given is a triangle XYW, whose side WZ is extended to the point z,
We know that,
The sum of two opposite interior angles of a triangle is equal to the measure of exterior angle,
∠ 1 + 50° = 150°
∠ 1 = 100°
We know that, sum of the interior angles of a triangle is 180°
∠ 1 + ∠ 2 + 50° = 180°
150°-180° = ∠ 2
∠ 2 = 30°
Hence, the measure of the missing angles are 100° and 30°
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consider the following input-output table. p q r s 1 1 1 0 1 1 0 1 1 0 1 0 1 0 0 0 0 1 1 0 0 1 0 1 0 0 1 0 0 0 0 0 the output column, s, was created from the student id 21444368 using the algorithm: if id digit n (left-to-right) is an even integer, place a 0 in s, row n (top-down) if id digit n (left-to-right) is an odd integer, place a 1 in s, row n (top-down) create a similar table, but with s reflecting the result of the algorithm applied to your student id (do this on scratch paper). on the quiz essay: record your student id, id
The output column, S, of the given input-output table was created from the student ID 21444368 using an algorithm where if the student ID digit is an even integer, a 0 is placed in the corresponding row of column S, and if the student ID digit is an odd integer, a 1 is placed in the corresponding row of column S.
Student ID: 81725225
P Q R S
1 1 1 0
1 1 0 1
1 0 1 1
0 1 0 0
0 0 1 1
0 1 1 0
0 0 0 1
Student ID: 81725225
P: The first digit of my student ID is 8 so it is an even integer, therefore I place a 0 in row 1 of column P.
Q: The second digit of my student ID is 1 so it is an odd integer, therefore I place a 1 in row 2 of column Q.
R: The third digit of my student ID is 7 so it is an odd integer, therefore I place a 1 in row 3 of column R.
S: The fourth digit of my student ID is 2 so it is an even integer, therefore I place a 0 in row 4 of column S.
The resulting table is:
P Q R S
1 1 1 0
1 1 0 1
1 0 1 1
0 1 0 0
0 0 1 1
0 1 1 0
0 0 0 1
The output column, S, of the given input-output table was created from the student ID 21444368 using an algorithm where if the student ID digit is an even integer, a 0 is placed in the corresponding row of column S, and if the student ID digit is an odd integer, a 1 is placed in the corresponding row of column S. The same algorithm was applied to my student ID 81725225, resulting in the table shown above.
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#20 i need help with this question
Answer:
Step-by-step explanation:
tha answer is 69
#15 find the measure of angle P. I need help with this problem
The measure of ∠P is 96°.
What is an expression?An expression is a way of writing a statement with more than two variables or numbers with operations such as addition, subtraction, multiplication, and division.
Example: 2 + 3x + 4y = 7 is an expression.
We have,
∠P and ∠R are alternate angles.
Alternate angles are equal.
So,
∠P = ∠R
2x = x + 48
2x - x = 48
x = 48
Now,
∠P = x + 48
∠P = 48 + 48
∠P = 96
Tus,
The value of ∠P is 96°.
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which has the lowest price per unit.
$23.35 per 6.5 lbs.
$31.60 per 8 lbs.
A sunflower is measured at the beginning of June and is 40cm tall. The sunflower
grows by 25% each month for three months. What height is the sunflower to the nearest
centimetre at the beginning of September?
Answer:
78cm 78.125
Step-by-step explanation:
Answer: 78.13
Step-by-step explanation:
you start with 40cm and find 25% of that and add it to 40cm. Or you can do 1.25x40=50 That would be July, so repeat to get 50x1.25=62.5 to get august, then again to get 62.5x1.25=78.13
A company is expanding its team at a rate of 10% per year. 17 a) Calculate how many members of staff there will be after 1 year if there are initially 200 members of staff.
Step-by-step explanation:
If a company is expanding its team at a rate of 10% per year, and it currently has 200 members of staff, we can calculate the number of staff after 1 year using the formula:
number of staff after 1 year = 200 + (10/100) * 200
number of staff after 1 year = 200 + 20
number of staff after 1 year = 220
So, there will be 220 members of staff after 1 year if there are initially 200 members of staff.
4 Four boys and five girls went to the movies together. Between them they
had $120 to spend. Tickets cost $8 each. How much money did they have
to buy refreshments?
Determine constants and such that the given piecewise function is continuous for all .
F(x)= -6 if x < -1
Ax + 2. if -1 ≤ x ≤ 2
-x^2 + Bx + 14. if x > 2
Round your answers to one decimal place, if necessary.
Answer: To make the piecewise function continuous for all x, we need to make sure that the function values and the function slopes at the boundaries (-1 and 2) are the same for each piece.
For x = -1:
F(-1) = -6 (from the first piece)
F(-1) = A(-1) + 2 = -A + 2 (from the second piece)
So, to make the function continuous at x = -1, we need to set -6 = -A + 2, which gives us A = -8.
For x = 2:
F(2) = -x^2 + Bx + 14 (from the third piece)
F(2) = A(2) + 2 = 2A + 2 (from the second piece)
So, to make the function continuous at x = 2, we need to set -4 + 2B + 14 = 2A + 2, which gives us B = -5.
Now we can write the function with the constants that we found :
F(x) = -6 if x < -1
-8x + 2 if -1 ≤ x ≤ 2
-x^2 - 5x + 14 if x > 2
This function is continuous for all x and the values and slopes match at x = -1 and x = 2.
Step-by-step explanation:
Find the equation for the plane through Po(-4,-3,8) perpendicular to the following line.
x = -4+t, y=-3-3t, z= -4t, -∞
The equation of plane is x - 3y - 4z = 27.
What method can be used to determine the equation of a plane that is perpendicular to a vector?a plane produced by the application of vectors perpendicular to a normal. The implication of this is that, given a vector a, b, c, we may deduce that all planes perpendicular to it have the form ax+by+cz=d and that any surface with this form is a plane perpendicular to a, b, c.
The equation for a plane perpendicular to a given line with direction ratios a, b, and c> and passing through a point is a(x-x1) + b(y-y1) + c(z-z1) = 0. (x1, y1, z1).
The equation of the plane traveling through the points x, y, and z on a plane perpendicular to the line whose parametric equation is provided
Equation of a plane through the point (-4,-3,8) is
a(x - 4) + b(y - 3) + c(z + 8) = 0
Since it is perpendicular to the line :
x = -4+t, y=-3-3t, z= -4t,
t = x + 4 = -y - 3 / 3 = -z/4
therefore coefficients a, b, c must be proportional to 1, - 3 & (-4) respectively.
Therefore, putting the values of a, b & c in eq.(1), we get the required equation of the plane as ;
λ(x - 4) -3 λ(y - 3) - 4λ(z + 8) = 0 (λ is a constant)
⇒ x - 4 - 3y + 9 -4z - 32 = 0
⇒ x - 3y - 4z = 27
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For the rectangular parking area of the shopping
center shown, which one of the following equations
says that the area is 30,000 yd² ?
A. x(4x +300) = 30,000
B. x+(4x +300)=30,00
Equation
(Type A, B, C, or D.)
says that the area is 30,000 yd².
CO
C. 2x + 2(4x + 300) = 30,000
D. x² (4x+300)² = 30,000²
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For the rectangular parking area of the shopping center shown, an equation which says that the area is 30,000 yd² is: A. x(2x + 200) = 30,000.
How to calculate the area of a rectangle?Mathematically, the area of a rectangle can be calculated by using this formula:
A = LW
Where:
A represents the area of a rectangle.W represents the width of a rectangle.L represents the length of a rectangle.From the information provided about the rectangular parking area of the shopping center shown in the image attached below, we have the following dimensions:
Length = x
Width = 2x + 200
Substituting the given points into the area of rectangle formula, we have the following;
30,000 = x × (2x + 200)
30,000 = x(2x + 200) ⇒ (required equation).
30,000 = 2x² + 200x.
2x² + 200x - 30,000 = 0.
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