The math department recently purchased new learning software for their freshman math classes. The instructors want to use the learning software instead of a textbook. So they decide to study the effectiveness of the software. First they test the skills and concept mastery for a number of the freshman math students. Then they randomly divide the students into two groups. One group uses the learning software for a particular lesson and the other group uses the regular textbook. Then the instructors retest all of the students and compare the improvement in the skills and concept mastery for the two groups. What is the purpose of random assignment in this experiment? Check all that apply.
Options :
A.) To avoid bias
B. To control for confounding variables
C. To produce treatment groups with similar characteristics
D. To generalize the experiment results to all freshman math students
Answer:
To avoid bias
To generalize the experiment results to all freshman math students
Step-by-step explanation:
One of the most common problems with statistical experimental research is the issue posed by bias. Either selection bias or assignment bias. Bias creeps into our experiment when one experimental group is more favored than the other. This means that the strategy employed is not totally random. In the experimetal design explained above, students were randomly assigned to group in other to avoid bias. This random assignment ensures that all samples have equal probability of being assigned to any of the two groups.
Randomized experimental designs also allows for making a good estimate of the population parameter fromnthe sample statistic
The number of siblings a student has and the grades they have in math class.
A.
Positive correlation
B.
Negative correlation
C.
No correlation
Lily took out a 5-year loan from the bank for 31000.00 to purchase a new car. At the end of the loan, she paid a total of 37975. Find the interest rate on the loan.
Answer:
24.5%
Step-by-step explanation:
Simple Interest = (principal×rate×time)÷100. *Brackets First*
Transpose the formula to make rate the subject: rate= (100×simple interest) ÷ (principal×time).
Plug in values: rate = (100×37975) ÷ (31000×5).
The result is 24.5%.
Racial dimorphism mesning
Answer:
Facial sexual dimorphism emerges at puberty: as the size and shape of the male and female faces increase with age, faces begin to show different secondary sexual characteristics (i.e., masculine or feminine).
Suppose that you live in a community that has 125,000 households. Among these households, 50,000 have traditional landline telephones while the remaining 75,000 only use cellular and / or VOIP telephones. We are going to select 100 households from your community at random without replacement. The first household selected does not have a traditional landline telephone. What is the probability that the second household selected will have a traditional landline telephone
Answer:
0.4 = 40% probability that the second household selected will have a traditional landline telephone
Step-by-step explanation:
A probability is given by the number of desired outcomes divided by the number of total outcomes.
We have that:
125,000 households
50,000 have traditional landlines telephones.
The first household selected does not have a traditional landline telephone.
Now we have 125000 - 1 = 124,999 households, and 50,000 have traditional landlines telephones.
What is the probability that the second household selected will have a traditional landline telephone
[tex]p = \frac{50000}{124999} = 0.4[/tex]
0.4 = 40% probability that the second household selected will have a traditional landline telephone
if the mean of the numbers 2x,3x,4x and 3x is 12,then the sum of the numbers is?
a)4
b)12
c)48
d)80
Answer:
C. 48.
Step-by-step explanation:
If the mean is 12, then 12 must be 2x, 3x, 4x, and 3x divided by 4.
--> [tex]\frac{2x+3x+4x+3x}{4}=12[/tex]
--> [tex]\frac{12x}{4}=12[/tex]
--> [tex]\\3x=12[/tex]
--> x=4
Add: 2x+3x+4x+3x=8+12+16+12=48
(DUE TODAY) Paul wants to build this model with clay, but he does not know how much clay to purchase. Draw a line to separate the model into two rectangular prisms. Then write an expression for the volume of the model. What is the volume?
Answer:
first draw a horizontal line through the middle, (you prob know where)
top prism: 5x4x5
bottom prism: 9x5x3
volume: 5x4x5+ 9x5x3
=235cm²
Step-by-step explanation:
There you go, hope this helps!
A drawing has a scale of 1 : 40
On the drawing, a kitchen is a rectangle measuring 14cm by 22cm.
A bedroom has an actual area of 500,000 cm ^2.
How much smaller,in cm^2 is the kitchen than the bedroom ?
Answer:
do you maybe have a picture to go with this??
Seven times the difference of a number and 7
Answer:
7 (x-7) or 7x-49
The cost of $500,000 worth of 15-year term life insurance for Audrey is
$28.44 per month. If Audrey's employer covers 75% of this cost, how much is
deducted from Audrey's gross income per year for life insurance?
A. $21.33
B. $85.32
C. $341.28
D. $255.96
SUBMIT
Ive been staring at this for a long time now, pls help
Answer:
9
Step-by-step explanation:
I replaced the missing variable with x and solved the equation from there.
Answer:
10.75
Step-by-step explanation:
i got this because the first part says 13 × 3/8 so this means that the numbers 2 × 3/8 + 3/8 + 3/8 and the unknown number have to equal 13. so when u multiply 2 x 3/8 you get .75 and then you add the two other numbers and get 1.5 and then you subtract 1.5 from 13 and you get 11.5
PHEWW
M M m Given the following triangle with the following angle values, solve for X,
Answer: x = 32
Step-by-step explanation:
Triangle angle sum theory states that the interior angles of a triangle sum to 180. Add all three angles up and set equal to 180 to solve.
33+ 37 + (3x+14) = 180. Combine like terms
84 +3x = 180. Subtract 84 from both sides.
3x = 96. Divide both sides by 3.
X = 32
Corrine earned $67.25 waiting tables, plus another $45.45 in tips. How much did she earn altogether?
Answer:
$112.70
Step-by-step explanation:
$67.25 + $45.45 = $112.70
How do you simplify 32/48
Answer:
2/3
Step-by-step explanation:
divide numerator and denominator by 16
32÷16=2
48÷16=3
answer is 2/3
Thus, 2/3 is the simplified fraction for 32/48 by using the GCD or HCF method. Thus, 2/3 is the simplified fraction for 32/48 by using the prime factorization method.
please help i've benn stuck on these questions for hours and it's due today
Answer:
1st one i think is B
the 2nd i think is C
2
Which of the following graphs represents a direct variation?
А
С
2
-4
-2
2
4
-2
2
-2
4
B
D
y
2
2
-2
2
4
2
4
-2
-2
Answer:
C & D
Step-by-step explanation:
Use the triangle below to answer the following questions:
What is the area of the triangle?
6
2
3
Answer:
6
Step-by-step explanation:
Find the area of both triangles inside the bigger triangle and add them together.
Use the Pythagorean theorem to find the missing length of the leg in the smallest triangle:
a² + b² = c²
2² + b² = 3²
4 + b² = 9
5 = b²
2.2 ≈ b
Calculate the area of the smaller triangle:
1/2(bxh)
1/2(2 x 2.2)
1/2(4.4)
2.2
Calculate the area of the bigger triangle:
We know that the longer leg is 3.8 units because we were able to subtract the length of the smaller triangle's leg from 6.
1/2(bxh)
1/2(2 x 3.8)
1/2(7.6)
3.8
Add both areas to find the area of the largest triangle:
3.8 + 2.2 = 6
work out the size of angle x 101 degrees and 38 degrees
Answer:
the inside angle beside 101 is 180-101 = 79 degrees.
the angle beside x = 180-(79+38).
that is 63 degrees.
therefore the angle x = 180-63 that's
117 degrees
what is the shape and direction of f(x)=(x+7)(x+11)
Given:
The function is
[tex]f(x)=(x+7)(x+11)[/tex]
To find:
The shape and direction of the given function.
Solution:
We have,
[tex]f(x)=(x+7)(x+11)[/tex]
It can be written as
[tex]f(x)=x^2+11x+7x+77[/tex]
[tex]f(x)=x^2+18x+77[/tex]
It is a quadratic function and the power of [tex]x[/tex] is 2 so the graph of this function is a vertical parabola.
The leading coefficient is positive so the parabola opens upward.
Therefore, the given function is a vertical parabola that opens upward.
simplify the expression -2d + -2d - 9 + -9
Answer:
-4d-18
Step-by-step explanation:
Combine like terms:
-2d and -2d can combine since they have the same variable of d creating the term of -4d and -9 and -9 can combine to create -18. Put those together and you get the answer above.
Answer:
-4d-18
Step-by-step explanation:
Does the table represent an exponential function? Explain why or why not.
(3,-10 ), (4,-7 ), (5,-4), (6,-1), (7,2),(8,5)
Answer:
No, it does not.
Step-by-step explanation:
It's a linear function, with a slope of -3 (down 3 for every new X as you move right)
lol please help i literally cannot do math to save my life
Answer:
[tex]\displaystyle d \approx 3.6[/tex]
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightAlgebra I
Reading a Cartesian Plane
Coordinates (x, y)Algebra II
Distance Formula: [tex]\displaystyle d = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]Step-by-step explanation:
Step 1: Define
Find points from graph.
Point A(-2, 1)
Point B(1, -1)
Step 2: Find distance d
Simply plug in the 2 coordinates into the distance formula to find distance d
Substitute in points [Distance Formula]: [tex]\displaystyle d = \sqrt{(1+2)^2+(-1-1)^2}[/tex][Distance] [√Radical] (Parenthesis) Add/Subtract: [tex]\displaystyle d = \sqrt{(3)^2+(-2)^2}[/tex][Distance] [√Radical] Evaluate exponents: [tex]\displaystyle d = \sqrt{9+4}[/tex][Distance] [√Radical] Add: [tex]\displaystyle d = \sqrt{13}[/tex][Distance] [√Radical] Evaluate: [tex]\displaystyle d = 3.60555127546[/tex][Distance] Round: [tex]\displaystyle d \approx 3.6[/tex]Answer:
3.6 units
Step-by-step explanation:
Point A --> [tex]x_{1} \\[/tex] = -2 , [tex]y_{1}[/tex] = 1
Point B --> [tex]x_{2}[/tex] = 1 , [tex]y_{2}[/tex] = -1
AB =
[tex]\sqrt{(x_{2} - x_{1})^2 + (y_{2} - y_{1})^2 } \\\sqrt{[1 - (-2)]^2 + [(-1) - 1]^2} \\\sqrt{3^2 + (-2)^2} \\\sqrt{9 + 4} \\ \sqrt{13} \\3.605[/tex]
distance between AB can be rounded to 3.6 units
Hope it helps.
Solve for x:
X х+ 9 = 5x — 11
Answer:
5
Step-by-step explanation:
x+9-(5*x-11)=0
-4x + 20 = -4 • (x - 5)
-4 = 0
x-5 = 0
Add 5 to both sides of the equation :
x = 5
The figure below consists of a square and a right triangle. Find the missing length x.
What is the interquartile in the dot plot for Mrs. Orlando’s daycare? i need thisssss!!
use long division to find the value of 1,875÷15
Answer:
Step-by-step explanation:
Answer:
125
Step-by-step explanation:
can you help me on a papper
Answer:what do you need help with
Step-by-step explanation:
Please can someone answer this I don’t get it!!! 5 points and Brainly:)
Answer:
the answer will be 39cm yes
A commuter airline makes lattes in the galley and sells them to passengers. A regular latte contains a shot of espresso, 1 cup of 2% milk, steamed, and 0.5 cup of whipped cream. The low-fat latte contains a shot of espresso, 1.25 cups of skim milk, frothed, and no whipped cream. The plane begins its journey with 100 shots of espresso, 60 cups of skim milk, 60 cups of 2% milk, and 30 cups of whipped cream. The airline makes a profit of $1.58 on each regular latte and $1.65 on each low-fat latte. Assuming that all lattes that are made can be sold, what would be the ideal mix of regular and low-fat lattes to maximize the profit for the airline?
Answer:
To maximize profit, the amount of each type of coffees made are;
The number of regular latte made = 52 cups
The number of low-fat latte made = 48 cups
Step-by-step explanation:
The given parameters are;
The number of espresso in a regular latte = 1 shot
The number of cups of 2% milk in regular latte = 1 cup
The amount of whipped cream in a regular latte = 0.5 cup
The number of cups of skim milk in the low-fat latte = 1.25 cup
The number of espresso in a low-fat latte = 1 shot
The amount of whipped cream in a low-fat latte = 0 cup
The number of cups of espresso in the journey = 100 shots
The number of cups of skim milk in the journey = 60 cups
The number of cups of 2% milk in the journey = 60 cups
The amount of profit the airline makes on each regular latte = $1.58
The amount of profit the airline makes on each low-fat latte = $1.65
Let 'x' represent the number regular lattes made and let 'y' represent the number low-fat lattes made, we have;
x ≤ 30/0.5 = 60
x ≤ 60
y ≤ 60
y ≤ 60/1.25 = 48
∴ y ≤ 48
x + y ≤ 100
Therefore, the given that more profit is made from the sale of low-fat latte than for regular latte, the maximum number of low-fat latte should be made
Therefore, the number of low-fat latte made, y = 48
Therefore, the number of regular latte made, x ≤ 100 - 48 = 52
For maximum profit, the maximum number of low-fat latte, 'x', should be made
Therefore, x = 52
The ideal mix of regular and low-fat lattes to maximize profit is 52 cups of regular latte and 48 cups of low-fat latte