Which of the following is an example of a matched pairs design? A. A teacher calculates the average scores of students on a pair of tests and wishes to see if this average is larger than 80%. B. A teacher compares the pre-test and post-test scores of students. C. A teacher compares the scores of students using a computer based method of instruction with scores of other students using a traditional method of instruction. D. A teacher compares the scores of students in her class on a standardized test with the national average score.
Answer:
B. A teacher compares the pre-test and post-test scores of students
Step-by-step explanation:
the answer is true, because it is a good example to compare the tests between students, we know that a matching pair design is a random model and is used when the experiment allows grouping subjects in pairs based on a variable and each pair will receive randomly a different handling, the answer A is not true because in the example all students are uniformly averaged and the variable is not correlated with subgroups, option c is incorrect because the variable was not randomized and generates classification bias and the option d is incorrect because the teacher compares a small sample as her class with a score of a total sample, but does not intervene on her students when selecting the corresponding group
Matched pair design describes an experimental technique whereby subjects having certain variable or characteristic are paired or matched based on that variable, usually called the key variable. Hence, an example of a matched pair design is "a teacher compares the pre-test and post-test scores of students."
In these type of experimental design, the key or common variable pertinent to both matched subjects is of utmost importance. The only option where, the variable shared is common is the pretest and posttest scores. In the other options, comparing traditional and computer based instructions doesn't match ; similarly, standardized score and national average do not match perfectly.Hence, the most appropriate option is A.
Learn more : https://brainly.com/question/19445381
Two terms of an arithmetic sequence are a12=70 and a30=124. Write an explicit rule for the nth term.
Answer:
Tn = 34-3nStep-by-step explanation:
The formula for calculating the nth term of an arithmetic sequence is given as;
Tn = [tex]a+(n-1)d[/tex]
a is the first term
n is the number of terms
d is the common difference
If two terms of an arithmetic sequence are a12=70 and a30=124 then;
T12 = a+(12-1)d = 70
T12 = a+11d = 70...(1)
T30 = a+(30-1)d = 124
T30 = a+29d = 124...(2)
Solving equation 1 and 2 simultaneously to get a and d;
Taking the difference of both equation we have;
29d - 11d = 124-70
18d = 54
d = 54/18
d = 3
Substituting d=3 into equation 1 to get the value of 'a' we have;
a+11(3) = 70
a+33=70
a = 70-33
a = 37
To get the explicit rule for the nth term of the sequence, we will use the formula Tn = a+ (n-1)d where a = 37, d =3
Tn = 37+(n-1)3
Tn = 37+3n-3
Tn = 34-3n
This gives the required nth term
A number pattern starts with 10 and follows the rule "multiply by 3." What is true
about all of the numbers in this pattern?
Water is leaking out of an inverted conical tank at a rate of 8200.08200.0 cm3/min cm3/min at the same time that water is being pumped into the tank at a constant rate. The tank has height 11.0 m11.0 m and the the diameter at the top is 4.5 m4.5 m. If the water level is rising at a rate of 16.0 cm/min16.0 cm/min when the height of the water is 3.0 m3.0 m, find the rate at which water is being pumped into the tank in cubic centimeters per minute. Answer: cm3/min
Answer:
I' = 197,474.47 cm^3/min
the rate at which water is being pumped into the tank in cubic centimeters per minute is 197,474.47 cm^3/min
Step-by-step explanation:
Given;
Tank radius r = d/2 = 4.5/2 = 2.25 m = 225 cm
height = 11 m
Change in height dh/dt = 16 cm/min
The volume of a conical tank is;
V = (1/3)πr^2 h .....1
The ratio of radius to height for the cone is
r/h = 2.25/11
r = 2.25/11 × h
Substituting into equation 1.
V = (1/3 × (2.25/11)^2)πh^3
the change in volume in tank is
dV/dt = dV/dh . dh/dt
dV/dt = ((2.25/11)^2)πh^2 . dh/dt ....2
And change in volume dV/dt is the aggregate rate at which water is pumped into the tank.
dV/dt = inlet - outlet rate
Let I' represent the rate of water inlet and O' represent the rate of water outlet.
dV/dt = I' - O'
Water outlet O' is given as 8200 cm^3/min
dV/dt = I' - 8200
Substituting into equation 2;
I' - 8200 = ((2.25/11)^2)πh^2 . dh/dt
I' = ((2.25/11)^2)πh^2 . dh/dt + 8200
h = 3.0 m = 300 cm (water height)
Substituting the given values;
I' = ((2.25/11)^2)×π×300^2 × 16 + 8200
I' = 197,474.47 cm^3/min
the rate at which water is being pumped into the tank in cubic centimeters per minute is 197,474.47 cm^3/min
Figure A is translated 3 units right and 2 units up. The translated figure is labeled figure B. Figure B is reflected over the x-axis. The reflected figure is labeled figure C. Which best explains why figure A is congruent to figure C? On a coordinate plane, triangle A has points (1, negative 2), (3, negative 2), (3, negative 5). Triangle B has points (4, 0), (6, 0), (6, negative 3). Triangle C has points (4, 0), (6, 0), (6, 3). A Is congruent to B and B Is congruent to C A Is congruent to A, B Is congruent to B, C Is congruent to C Each triangle is a right triangle. Each triangle is an isosceles triangle.
Answer:
A Is congruent to B and B Is congruent to C
Step-by-step explanation:
Let's look at the answer choices:
A: "A Is congruent to B and B Is congruent to C"
Well, clearly, if A ≅ B and B ≅ C, then by the transitive property, we can say that A ≅ C. So, A is very likely correct.
B: "A Is congruent to A, B Is congruent to B, C Is congruent to C"
Just because A is congruent to itself (and same with B and C) doesn't necessarily mean that they're congruent to each other. So, B is wrong.
C: "Each triangle is a right triangle."
Again, there are so many right triangles out there with different dimensions. For example, there are some with sides 3, 4, and 5, and others with sides 5, 12, and 13. They are not congruent, however. So, rule out C.
D: "Each triangle is an isosceles triangle."
This is just like choice C since there are so many variations of isosceles triangles. So D is wrong.
The answer is thus A.
Answer:
First one:
A Is congruent to B and B Is congruent to C
Step-by-step explanation:
Since B is obtained by translating A, it has the same measure angles and sides as A, hence B is congruent to A
C is obtained by reflecting B, which doesn't alter the measure of sides and angles, so C is congruent to B
Therefore by transition, C is congruent to A
A movie membership costs $10 a month plus an additional $5 for each movie purchased. If you have only budgeted to spend a maximum of $25 this month, how many movies can you purchase?
Answer:
3
Step-by-step explanation:
25-10/3=3
Answer:
3 movies
Step-by-step explanation:
You can pay for 3 movies because
5*3=15 and you have to pay for the membership which is 10 so
10+15=25
OMG THIS QUESTION IS SO HARD WILL RATE IF U GET IT
Answer:
19.5 in²
Step-by-step explanation:
Area of rhombus tile = side × height
Area = 3 × 6.5
Area = 19.5 in²
A rhombus, like any parallelogram, has area equal to base times height,
that's 3×6.5 = 19.5 square inches
Answer: 19.5
During Ashland High School basketball games, the snack bar sells both cheese and pepperoni pizza slices. Last night, the snack bar sold 143 slices of pizza. They sold 10 times as many pepperoni slices as cheese slices.
How many slices of cheese pizza did the snack bar sell last night?
slices of cheese pizza
Answer:
13 slices of cheese pizza
Step-by-step explanation:
Consider grouping the slices so there are 10 pepperoni and 1 cheese in each group of 11. Then 143 slices represents 143/11 = 13 groups. Since there is 1 cheese slice in each group, ...
13 slices of cheese pizza were sold
Type the correct answer in each box. Use numerals instead of words. If necessary, use / for fraction bar(s)
f(x) {____if -1_< x _<1
____if 3_< x _<5
Answer: f(x) = 4 if -1 ≤x ≤ 1
f(x) = x - 1 if 3≤ x ≤ 5
Step-by-step explanation:
if -1 ≤x ≤ 1
We can see that in this range the function is constant, f(x) = 4
if 3≤ x ≤ 5
In this region we can see a linear relationship, with the points (3, 2) and (5, 4)
as the extremes, we can find the slope of this linear equation as:
s = (4 - 2)/(5 - 3) = 2/2 = 1
So our equation is
f(x) = 1*x + b
to find the value of b we can evaluate our function in the first point, we know that when x = 3, y = 2, so we have:
2 = 1*3 + b
b = 2- 3 = -1
then f(x) = 1*x - 1
Then we have:
f(x) = 4 if -1 ≤x ≤ 1
f(x) = x - 1 if 3≤ x ≤ 5
Find the area of a semi-circle with radius, r = 83cm.
Give your answer rounded to 1 DP.
The cone in the diagram has the same heght and base area as the prism. What is the ratio of the volume of the cone to the volume of the
prism
base area =B
base area =
DA
volume of cone
volume of prism
B volume of cone
volume of prism
1
3
Ос
volume of cone
នាង
Bones reserved
Answer:
1/3
Step-by-step explanation:
The volume of a prism in terms of base area (B) and height (h) is ...
V = Bh
The volume of a cone in terms of base area (B) and height (h) is ...
V = (1/3)Bh
Then the desired ratio is ...
cone volume / prism volume = ((1/3)Bh)/(Bh) = 1/3
The ratio of the volume of the cone to the volume of the prism is 1/3.
Apply distributive property to factor out the greatest common factor.
Explanation:44h-33 I need an answer?
Answer:11(4h-3)
Step-by-step explanation:
44h-33
11(4h-3)
Line parallel to the y-axis that passes through the point (77,88)
Answer:
A line which is parallel to the y-axis has form of x = a
This line passes (77, 88), then a = 77
=> The equation of this line: x = 77
Hope this helps!
:)
The population of a town increased from 3450 in 2006 to 4650 in 2011. Find the absolute and relative (percent) increase.
Answer:
15% increase per year.
Step-by-step explanation:
5,600 - 3,500 = 2,100
2,100 is what percent of 3,500?
2,100 = X*3,500
X = 2,100 / 3,500
X = .60 or 60%
An average of 15% increase per year.
Answer:
the population of a town increased from 3450 and 2006 to 51,50 and 2010 find the absolutes and relative percent increase
Step-by-step explanation:
The graph of a function is shown below.
D
Which statement best describes section D of the graph?
0 А.
linear and increasing
О В.
linear and decreasing
Ос.
nonlinear and increasing
OD
nonlinear and decreasing
Theater tickets cost $16 for general admission or $9 with a student ID.
Total ticket sales for a certain showing was $4983. Write an equation
in standard form that shows the possible number of general
admission tickets, x, and student tickets, y, that were sold. Then, find
the total number of student tickets sold if 240 were general
admission tickets.
Answer:
127 student tickets
Step-by-step explanation:
16x + 9y = 4983
x = 240, so substitute that in.
16(240) + 9y = 4983
3840 + 9y = 4983, substract 3840 from both sides
9y = 1143, then divide both sides by 9
y = 127 student tickets
Answer: 16x + 9y = 4983
240 general admission tickets and 127 student tickets
Step-by-step explanation: If you already know that there are 240 general admission tickets and general admission tickets cost 16 dollars the multiply 16 times 240 to get 3840
then subtract 4983 - 3840 to get 1143 which is the money earned on students so now divide 1143 by 9 to get 127
hope this helps mark me brainliest if it did
A footbridge has a span of 54 feet. A sign is
to be placed exactly halfway across the bridge. How far will the center of the sign be from each end of the bridge?
Answer:
27
Step-by-step explanation:
Because if it is halfway, that means
halfway=1/2
1/2=1/2 of 54
54/2 or 1/2 of 54=27
PLS MARK ME BRAINLIEST I NEED IT PLEASE
The center of the sign will be 27 feet apart from both ends of the bridge.
Given that,
A footbridge has a span of 54 feet. A sign is to be placed exactly halfway across the bridge. How far will the center of the sign be from each end of the bridge is to be determined.
In mathematics, it deals with numbers of operations according to the statements. There are four major arithmetic operators, addition, subtraction, multiplication, and division,
Here,
Since the bridge is 54 feet long,
Now at the center of the bridge, a sign is placed,
So the distance of sign from both ends is equal to half of the total length of the bridge. i.e.
= 54 / 2
= 27
Thus, the center of the sign will be 27 feet apart from both ends of the bridge.
Learn more about arithmetic here:
brainly.com/question/14753192
#SPJ2
What is the area of the triangle
Answer:
A. 6 inchesssssssss
Answer:
6
Step-by-step explanation:
Fill in the table using this function rule.
y= 3x - 3
Answer:
1. -3*-4+3= 15
Y=15
2.-3*-2+3=9
Y=9
3. -3*0+3=3
Y=3
4. -3*2+3= -3
Y= -3
What number is 4 time another. The sum of the reciprocals is 15/4. find the numbers
Answer:
3/4 , 3
Step-by-step explanation:
Let one number = x
Other = 4x
Sum:
x + 4x = 15/4
5x = 15/4
x = 3/4
Thus the numbers are 3/4 , 3
se x vale 3 quanto vale 2x
Answer:
6
Step-by-step explanation:
x=3
2x = 2(3) = 6
Can anyone help me with this?
Answer:
35 yards
Step-by-step explanation:
20yd+15yd
you add 20yd and the 15yd and that is your area.
To the nearest tenth of a cubic centimeter, what is the volume of
the sphere if r = 17 cm?
Answer:
V≈20579.53
Step-by-step explanation:
[tex]V=\frac{4}{3} \pi r^3[/tex]
Which expression is equivalent to m n + z?
n m + n
z + m z
m z + n
z + n m
Answer:
z + n m
Step-by-step explanation:
These expressions are equivalent because the commutative property of addition, which states that when adding two terms, the order doesn't matter.
If this answer is correct, please make me Brainliest!
Answer:
It's "c"
Step-by-step explanation:
i just did this on edge
Im a parent for a 5th grader and don't remember this, plz help?
Again,
Josh wants to make 5 airplane propellers. he needs 18 centimeters of wood for each propeller. how many centimeters of wood will he use? How can I help him understand this problem.
Answer:
90 cm.
Step-by-step explanation:
One airplane propeller needs 18 centimetres of wood.
Josh wants to make 5 of them.
So, we would have to take the '18' centimetres of wood and multiply by 5 to get the total for all 5 pieces.
[tex]\text{Number of Propellers} * 18 \text{ Centimetres}[/tex]
[tex]5 * 18 = 90[/tex]
Josh should need 90 centimetres of wood total to make 5 airplane propellers.
show more notes w. heieie you can do it for
Answer:
Scallops
Step-by-step explanation:
At 3:30 P.M., the water level in a pool is 14 inches. At 4:00 P.M., the water level is 20 inches. At 5:00 P.M., the water level is 32 inches. What is the constant rate of change?
Answer: Per 1/2 an hour it is changes by 5 so the constanT rate would be: 5 inches per 1/2 an hour
A celebrity called Wayne East has been having some money problems recently. He is thinking of investing in the greatest record in the world, and wants to know how the value will change over time. He has an exponential regression model where his predictor is time in months, and response variable is money, measured in thousands of dollars. The alpha value is 4.2, and beta is 1.03. Based on this model, how much money (in thousands) will he have after six months
Answer:
Wayne west would have $5,015 in six months
Step-by-step explanation:
The formula for exponential regression model is y = αβˣ
Where y is amount of money in 1000 dollars
x is time in months
We are given that α = 4.2 and β = 1.03 and x = 6 months
Therefore, based on this model, y = αβˣ, the amount he would have in 6 months, y = [tex]4.2*(1.03) ^{6}[/tex]
y = 5.015 × 1000 = $ 5,015
Which sequence of transformations produces an image that is not congruent to the original figure?
A. A reflection across the x axis followed by a rotation of 180 counterclockwise
B. A translation of 6 units to the left followed by a reflection across the x-axis
C. A rotation of 90° clockwise followed by a translation of 4 units to the left
D. A translation of 4 units to the left followed by a dilation of a factor of 3
Answer:
D. A translation of 4 units to the left followed by a dilation of a factor of 3
Step-by-step explanation:
Of the transformations, rotation, reflection, translation, dilation, the first three (rotation, reflection, translation) are known as "rigid" transformations. They do not change the shape or size of the object. Any result of a rigid transformation is congruent to the original.
Dilation, by its nature, changes the size of the object, so the result is NOT congruent to the original.
Choice D includes dilation, so the image is not congruent to the original.
Find cos(a) in the triangle.
Choose 1 answer
Answer:
the correct answer is 35 / 37
