Answers
Related Questions
Suppose that a researcher using data on class size (CS) and average test scores from 100 thirdgrade classes, estimates the following OLS regression. Test̂Score = 520.4 − 5.82 × CS n = 100, R 2 = 0.08, SER = 11.5
a. A class has 22 students. What is the regression’s prediction for this classroom’s average test score?
b. Last year, a class had 19 students, and this year it has 23 students. What is the regression’s prediction for the change in the classroom average test score?
c. The sample average class size across the 100 classrooms is 21.4. What is the sample average of the test scores across the 100 classrooms?
d. What is the sample standard deviation of test scores across the 100 classrooms?
Answers
This question is incomplete, the complete question is;
Suppose that a researcher using data on class size (CS) and average test scores from 100 third grade classes, estimates the following OLS regression. Test-Score = 520.4 - 5.82 × CS, n = 100, R² = 0.08, SER = 11.5
a. A class has 22 students. What is the regression's prediction for this classroom's average test score?
b. Last year, a class had 19 students, and this year it has 23 students. What is the regression's prediction for the change in the classroom average test score?
c. The sample average class size across the 100 classrooms is 21.4. What is the sample average of the test scores across the 100 classrooms?
d. What is the sample standard deviation of test scores across the 100 classrooms?
Answer:
a)
the regression's prediction for this classroom's average test score is 392.36
b)
the regression's prediction for the change in the classroom average test score is -23.28
c)
the sample average of the test scores across the 100 classrooms is 395.852
d)
the sample standard deviation of test scores across the 100 classrooms is 11.92887
Step-by-step explanation:
Given the data in the question;
Test-Score = 520.4 - 5.82 × CS, n = 100, R² = 0.08, SER = 11.5 -----1
the general formula for the average test score is as follows;
Test score = ^β₀ + ( ^β₁ × CS ) -------- 2
the general for change in test score ;
ΔTest Score = β[tex]_{ class-size[/tex] × ΔClass size -------- 3
General formula for the sum of squared residuals SSR
SSR = ( n - 2 ) SER² ----- 4
General formula for total sum of squares TSS
TSS = SRR / 1 - R² -------- 5
General formula for sample standard deviation;
Sy = √(TSS / (n-1) ) ------ 6
now, from the given formula;
^β₀ = 520.4
aslo, β[tex]_{ class-size[/tex] = ^β₁ = - 5.82
so
a) A class has 22 students. What is the regression's prediction for this classroom's average test score?
given that class size CS is 22, to get the regression's prediction for this classroom's average test score, we make use of formula 2 above;
Test score = ^β₀ + ( ^β₁ × CS )
so we substitute
Test score = 520.4 + ( -5.82 × 22 )
Test score = 520.4 + ( - 128.04 )
Test score = 520.4 - 128.04
Test score = 392.36
Therefore, the regression's prediction for this classroom's average test score is 392.36
b) Last year, a class had 19 students, and this year it has 23 students. What is the regression's prediction for the change in the classroom average test score.
we make use of formula 3 above
ΔTest Score = β[tex]_{ class-size[/tex] × ΔClass size
we substitute
ΔTest Score = -5.82 × ( 23 - 19 )
ΔTest Score = -5.82 × 4
ΔTest Score = -23.28
Therefore, the regression's prediction for the change in the classroom average test score is -23.28
c) The sample average class size across the 100 classrooms is 21.4. What is the sample average of the test scores across the 100 classrooms?
we make use of formula 2 above;
Test score = ^β₀ + ( ^β₁ × CS )
we substitute
Test score = 520.4 + ( -5.82 × 21.4 )
Test score = 520.4 + ( -124.548 )
Test score = 520.4 - 124.548
Test score = 395.852
Therefore, the sample average of the test scores across the 100 classrooms is 395.852
d) What is the sample standard deviation of test scores across the 100 classrooms.
first we make use of formula 4 above; to calculate the sum of squared residuals SSR
SSR = ( n - 2 ) SER²
we substitute
SSR = ( 100 - 2 ) (11.5)²
SSR = 98 × 132.25
SSR = 12,960.5
Also, for total sum of squares TSS, we use formula 5
TSS = SRR / 1 - R²
we that R² = 0.08; from the given formula
so we substitute
TSS = 12,960.5 / 1 - 0.08
TSS = 12,960.5 / 0.92
TSS = 14087.5
so, the sample standard deviation will be;
from formula 6 above
Sy = √(TSS / (n-1) )
we substitute
Sy = √(14087.5 / (100-1) )
Sy = √(14087.5 / 99)
Sy = √142.297979
Sy = 11.92887
Therefore, the sample standard deviation of test scores across the 100 classrooms is 11.92887
review the graph. What is the component form and direction of the vector shown
a.) ⟨7,-3⟩ and 23 degrees
b.) ⟨-7,3⟩ and 23 degrees
c.) ⟨7,-3⟩ and 157 degrees
d.) ⟨-7,3⟩ and 157 degrees
Answers
Answer:
D
Step-by-step explanation:
Ed2021
Marcy sees a game, Rolling-in-Gold, in which a contestant rolls a
cube with five red sides one gold side. A player wins the game
by rolling a gold. Is Rolling-in-Gold a fair game? If not, how
could the game be made fair? Explain.
Answers
Answer:
it's not fair, because it's only a 1 in 6 chance of rolling gold.
it would be fair if 3 of the 6 sides were gold
Answer:
it aint fair it only 1/6 listen to the other guy
Step-by-step explanation:
i needed points sorry
The sum of four numbers is 540. One of the
numbers, x, is 50% more than the sum of the other
three numbers. What is the value of x?
Answers
Answer:
chale. necesita. 20 caracteres
A value of 0.5 that is added to and/or subtracted from a value of x when the continuous normal distribution is used to approximate the discrete binomial distribution is called Group of answer choices probability density factor. factor of conversion. continuity approximation factor. continuity correction factor.
Answers
Answer:
continuity correction factor
Step-by-step explanation:
A value of 0.5 that is added to and/or subtracted from a value of x when the continuous normal distribution is used to approximate the discrete binomial distribution is called continuity correction factor.
Reason -
A continuity correction factor is used when you use a continuous probability distribution to approximate a discrete probability distribution.
It’s brainiest time ! One thing to do!
Answers
Answer:
116.4545454545455
Step-by-step explanation:
There are 3 girls for every 2 boy at a party. There are 20 boys at the party.how many girl are there
Answers
Answer:
there will be 30 girls at the party
Answer:
There are 30 girls at the party.
Step-by-step explanation:
20 / 2 = 10
10*3 = 30
You divide the 20 boys at the party from the "every 2 boys", and you should get 10.
You then multiply the 10 by 3, for the 3 girls at the party and you should get 30 as an answer, so therefore you should get 30 as your answer.
I need help fast please
Answers
Answer:
what
Step-by-step explanation:
where is the question its not showing
3.1.3 How far was the hiker at 10:30?
8km
ACTIVITIES
1. Siyabonga runs a car wash business. The monthly expenses for his business include:
R1 400,00 in salaries.
R5,20 per washed car, for water, soap and electricity.
Siyabonga charges R25,00 per car for a wash and vacuum.
1.1.White down a formula to represent the total monthly cost that Siyabonga incurs in running his car
wash business as dependent on the number of cars washed.
(2)
1.2.Write down a formula to represent the total monthly income that Siyabonga generates as dependent
on the number of cars washed.
(2)
1.3. Use trial and improvement to determine how many cars Siyabonga must wash per month in order to
break even and cover all business expenses.(2)
1.4.How much must Siyabonga earn in income per month in order to break even? (2)
1.5.The graphs below resent the total monthly cost and total income for Siyabonga's car wash business.
2.500
2,400
2,300
2 200
2,100
2,000
Answers
Answer:
[tex]y = 1400 + 5.2x[/tex] --- Running cost
[tex]y = 25 x[/tex] --- Monthly income
71 cars
R1775
Step-by-step explanation:
Given
Expenses
[tex]Salaries = 1400.00[/tex]
[tex]Others = 5.20[/tex] per car
Income
[tex]Rate = 25.00[/tex] per car
Solving (a): Expression for the running cost
This is calculated as:
[tex]y = Salary + Others * x[/tex]
Where
y = Total running cost
x = number of cars
So:
[tex]y = 1400 + 5.20 * x[/tex]
[tex]y = 1400 + 5.2x[/tex]
Solving (b): Expression for monthly income
This is calculated as:
[tex]y = Rate * x[/tex]
Where
y = Total income
x = number of cars
So:
[tex]y = 25.00 * x[/tex]
[tex]y = 25 x[/tex]
Solving (c): Break even
To do this, we equate the expressions in (a) and (b)
[tex]y = y[/tex]
[tex]25x = 1400 + 5.2x[/tex]
Collect Like Terms
[tex]25x -5.2x= 1400[/tex]
[tex]19.8x= 1400[/tex]
Solve for x
[tex]x = \frac{1400}{19.8}[/tex]
[tex]x = 71[/tex]
Solving (d): How much to break even
Substitute 71 for x in any of (a) or (b)
[tex]y = 25 x[/tex]
[tex]y = 25 * 71[/tex]
[tex]y = 1775[/tex]
Solving (e): There is no question to answer on the "graph"
Please help me find the answer.
Answers
Answer:
a = 16 and b = 2
Step-by-step explanation:
Help pleaseeeeeeee thanks
Answers
Answer:
so the answer is 5
Step-by-step explanation:
the equation will be for this is
7x + 20 = 55
7x = 55-22
7x = 35
x = 35÷7
x=5
All 10,000 California students in the beginning of 8th grade are given an entrance exam that will allow them to attend a top academic charter school for free. Students who achieve a score of 92 or greater are admitted. This year the mean on the entrance exam was an 82 with a standard deviation of 4.5. a.What is the percentage of students who have the chance to attend the charter school
Answers
Answer:
1.32% of students have the chance to attend the charter school.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
This year the mean on the entrance exam was an 82 with a standard deviation of 4.5.
This means that [tex]\mu = 82, \sigma = 4.5[/tex]
a.What is the percentage of students who have the chance to attend the charter school?
Students who achieve a score of 92 or greater are admitted, which means that the proportion is 1 subtracted by the pvalue of Z when X = 92. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{92 - 82}{4.5}[/tex]
[tex]Z = 2.22[/tex]
[tex]Z = 2.22[/tex] has a pvalue of 0.9868
1 - 0.9868 = 0.0132
0.0132*100% = 1.32%
1.32% of students have the chance to attend the charter school.
The number of vinyl album sales (in millions) in a country x years after 2010 can be modeled by y = 0.1242 + 0.32 +3.3
for 2010 through 2016. Use this model to predict the number of vinyl album sales in the country in the year 2020 where
(2 = 10) (1 point)
• The number of vinyl album sales in the country in the year 2020 will be 20.5 million
The number of vinyl album sales in the country in the year 2020 will be 18.3 million
The number of vinyl album sales in the country in the year 2020 will be 7.74 million
O The number of vinyl album sales in the country in the year 2020 will be 21.12 million
Answers
Answer:
b) The number of vinyl album sales in the country in the year 2020 will be 18.3 million.
Step-by-step explanation:
Given - The number of vinyl album sales (in millions) in a country x years after 2010 can be modeled by y = 0.12 x² + 0.3 x +3.3 for 2010 through 2016.
To find - Use this model to predict the number of vinyl album sales in the country in the year 2020 where x = 10
a) The number of vinyl album sales in the country in the year 2020 will be 20.5 million.
b) The number of vinyl album sales in the country in the year 2020 will be 18.3 million.
c) The number of vinyl album sales in the country in the year 2020 will be 7.74 million.
d) The number of vinyl album sales in the country in the year 2020 will be 21.12 million.
Proof -
Given that,
The equation be - y = 0.12 x² + 0.3 x +3.3
Now,
Put x = 10 in above equation we get
y = 0.12×10² + 0.3×10 +3.3
= 0.12×100 + 3 + 3.3
= 12 + 6.3 = 18.3
⇒y = 18.3
∴ we get
The number of vinyl album sales in the country in the year 2020 will be 18.3 million.
So,
The correct option be - b) The number of vinyl album sales in the country in the year 2020 will be 18.3 million.
what is 32x32x32x32x32x32x32x32
Answers
Answer:
1.0995116e+12
Step-by-step explanation:
Answer:
1,099,511,627,776
Step-by-step explanation:
32x32x32x32x32x32x32x32=1,099,511,627,776
How to solve this problem I need HELP!!!!
Answers
Answer:
a
Step-by-step explanation:
Answer:
to solve this problem I would convert -12/5 into the decimal -2.4 so that I could see it more clearly on the line graph.
after doing that it is easy to see that graph A. is the answer because it is the only one with points on -2.4 and -2.8
hope this helps <3
PLEASE HELP PLESD PLED
Answers
Answer:B
Step-by-step explanation: ok its B because i need some $$$
Answer:
D and E
Step-by-step explanation:
The question asks which one would always form an image that is congruent to the pre-image.
Note that Translation, Reflection, and Rotation do not change the size or shape of the pre-image while Dilation will change the size of your pre-image.
Therefore, the most likely answer would be options D and E that do not include dilation in their series of transformations so the image will not change its size making it congruent to the pre-image.
Three vertices of parallelogram DEFG are D(-4,-2), E(-3,1) and F(3, 3). Find the coordinates of G.
The coordinates of G are
Answers
Answer:
Coordinates of G = [tex](2,0)[/tex]
Step-by-step explanation:
Given: Three vertices of parallelogram DEFG are D(-4,-2), E(-3,1) and F(3, 3).
To find: coordinates of G
Solution:
Midpoints of a side joining points [tex](a,b),\,(c,d)[/tex] are given by [tex](\frac{a+c}{2},\frac{b+d}{2})[/tex]
Diagonals of a parallelogram bisect each other.
So,
Midpoint of DF = Midpoint of EG
Midpoint of DF = [tex](\frac{-4+3}{2},\frac{-2+3}{2})=(\frac{-1}{2},\frac{1}{2})[/tex]
Midpoint of EG = [tex](\frac{-3+x}{2},\frac{1+y}{2})[/tex]
Let coordinates of G be [tex](x,y)[/tex]
Therefore,
[tex](\frac{-1}{2},\frac{1}{2}) =(\frac{-3+x}{2},\frac{1+y}{2})\\\\\frac{-1}{2}=\frac{-3+x}{2},\,\frac{1}{2}=\frac{1+y}{2}\\\\-1=-3+x,\,1=1+y\\\\x=-1+3,\,y=1-1\\x=2,\,y=0[/tex]
So,
Coordinates of G = [tex](2,0)[/tex]
Find angle measure angle AEC?
Answers
Answer:
An arc is a segment of a circle around the circumference. An arc measure is an angle the arc makes at the center of a circle, whereas the arc length is the span along the arc. This angle measure can be in radians or degrees, and we can easily convert between each with the formula
π
r
a
d
i
a
n
s
=
180
°
.
Step-by-step explanation:
Find the slope and the y-intercept of the line. 2 y=- x+2 5
help please I need it now
Answers
Answer: Y = -x/2 + 12.5
Step-by-step explanation:
You wrote the equation strange so i don't really know if the end of the equation is a 25 or not
QUESTION 2
[16]
Given the sequence: 2; 5; 8; 11; 14...
Prove that none of the terms of this sequence are perfect squares.
PLEASE HELP!!
Answers
Answer:
✓2=1.41421
✓5=2.23607
✓8=2.82842
✓11=3.31662
✓14=3.74166
Step-by-step explanation:
Therefore the numbers are increasing by three so they cant be perfect square
9514 1404 393
Answer:
squares are of the form 3n or 3n+1; the sequence is of the form 3n-1, so none of the sequence will be a square
Step-by-step explanation:
The given arithmetic sequence has first term 2 and common difference 3, so its explicit formula is ...
an = 2 +3(n -1) = 3n -1 . . . . for counting numbers n
__
All integers are of one of these forms: 3n-1, 3n, 3n+1, for some integer n. The squares of these are ...
(3n -1)² = 9n² -6n +1 = 3(3n² -2) +1 = 3k+1 for some k
(3n)² = 3(3n²) = 3k for some k
(3n +1)² = 9n² +6n +1 = 3(3n² +2) +1 = 3k+1 for some k
Note that none of these squares is of the form 3n -1.
Hence, the square of an integer cannot be in the given sequence.
answer all three questions please
Answers
Answer:
A iS THE ANSWER
Step-by-step explanation:
Each of 5 friends got a full box of snacks and an extra 6 snacks. Write an equation to show how many snacks are in all those boxes and all those extra snacks.
Answers
This can be explained as x representing how much the five friends got and y equaling the total. Hope this helps!
What’s the dependent variable
Answers
Below is an example, it may help you! Goodluck.
Suppose your friends parents invest $20,00 in an account paying 5% compounded annually. What will the balance be after 8 years? The account balance will be $
Answers
Answer:
$2954.91 end of year eight
Step-by-step explanation:
2000 x 1.05^8 = 2000 x 1.04775 = $2954.91
Proof:
2000 x 1.05 = 2100 end of year one
2100 x 1.05 = 2205 end of year two
2205 x 1.05 = 2315.25 end of year three
2315.25 x 1.05 = 2431.01 end of year four
2431.01 x 1.05 = 2552.56 end of year five
2552.56 x 1.05 = 2680.19 end of year six
2680.19 x 1.05 = 2814.20 end of year seven
2814.20 x 1.05 = $2954.91 end of year eight
What is the answer of this question?
Answers
Answer:
Step-by-step explanation:
maybe D im not sure tho
Answer:
The answer is A)
You and your friend each deposit $50 in separate savings accounts. Your account earns 4% simple annual interest. Your friend’s account earns 6% simple annual interest. How long does it take for you to earn $12 in interest? How long does it take for your friend to earn $12 in interest?
Answers
ONLY 20 MIN LEFT HELPPPP!!!!
Which value is included in the solution set for the inequality graphed on the number line?
A. –5
B. –2
C. 0
D. 3
Answers
Answer:
A
Step-by-step explanation:
The inquality is
[tex]x < - 2[/tex]
So x can only be - 5
i need help. please, I do not understand much
Answers
Answer:
x ≥ -6
Domain is just all of the possible x values in a list
Median of 8,6,15,12,10,18,16
Answers
Answer:
12
Step-by-step explanation:
Mean 12.142857142857
Median 12
Mode 8, 6, 15, 12, 10, 18, 16
Range 12
Minimum 6
Maximum 18
Count n 7
Sum 85
Quartiles Quartiles:
Q1 --> 8
Q2 --> 12
Q3 --> 16
Interquartile
Range IQR 8
Outliers none
Why does the quotient of 8 ÷ 1 not change when we add a place value in the dividend and the divisor to make 80 ÷ 10?
Answers
Answer:
Basically this is because division can be thought of as how many times does the divisor have to be multiplied in order to produce the dividend.
So you would need to multiply 1 8 times in order to produce the dividend,
Similarly, 10 goes into 80 8 times. The zeros are simply cancelled out in the division.