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
21m42n32p10
Зm 21n16 р5
Simplify
Step-by-step explanation:
meh dont knowneed help understanding this question
Answer:
-9<x≤2
Step-by-step explanation:
The domain is the x values
If we look at the line, we see a closed circle when x=2, so x is less than or equal to 2
The other circle is open and is at -9, so x is greater than -9
-9<x≤2
Lemme know if u need more explanation!
the actual weights of bags of pet food are normally distributed about the mean of 50.0 lb with a standard deviation of 0.2 lb.
1. About what percentage of bags of pet food weigh between 49.8 lb and 50.2 lb?
2. About what percentage of bags weigh less than 49.8 lb?
3. In a group of 250 bags, what percentage of bags would you expect to weigh more than 50.4?
9514 1404 393
Answer:
68%16%2.5%Step-by-step explanation:
1. The empirical rule tells you 68% of the distribution is within 1 standard deviation of the mean. The mean is 50 and the standard deviation is 0.2, so this means 68% of the bags weigh between 49.8 and 50.2 lb.
__
2. The other 32% is evenly split above and below the central part of the distribution. That is, about 16% of the bags will weigh less than 49.8 lb.
__
3. The percentage is independent of the size of the group. The empirical rule tells you 95% lie within 2 standard deviations of the mean. The other 5% will be evenly split between those weighing more than 50.4 and those weighing less than 49.6 lb. About 2.5% of the bags will weigh more than 50.4 lb.
_____
Additional comment
It is useful to remember the empirical rule numbers, 68%, 95%, 99.7% for the portion of the distribution between ±1, 2, 3 standard deviations of the mean. They are useful for answering questions like this one. (They are only approximations, so if more accuracy is needed, a table or app should be used to find the accurate value.)
Someone please help me and thank you:)
Answer:
D
Step-by-step explanation:
Answer:
n+4=32 models this scenario.
This is because n+4 would show how many students are originally in the class.
Let me know if this helps!
Enter an algebraic equation for the word sentence. Use x as your variable.
A number increased by 7.9 is 8.5.
The equation is
x+7.9=8.5
solving x would be .6
if my answer helps please mark as brainliest.
Please help!!!!!!! *will mark Brainiest*
Answer:
-9/14
Step-by-step explanation:
I just used a calculator
Find the circumference of a button if its radius is 15 mm
Answer:
94.25mm
........................
Answer:
94.25 mm
Step-by-step explanation:
The circumfrence of a cirlce can be found using the following formula:
C = 2 x PI x R
Circumfrence = 2 x 3.14 x 15
= 94.25
X A doghouse is to be built in the shape of a right trapezoid, as shown below. What is the area of the doghouse?
A right trapezoid with top side 7 feet and height 7 feet. The bottom side is extended to the right with 5 more feet.
45.5 square feet 63 square feet 66.5 square feet 84 square feet
Answer:
Area of of the doghouse which is in the shape of right trapezoid is 66.5 square feet.
Step-by-step explanation:
Answer:
66.5 Squared feet
Hope it helps!
What is a scale and list two types of scale
Answer:
15 m. 30m
Step-by-step explanation:
there are two type
Helpppppppppppppppp
Find the measure of the arc or angle indicated assume that lines which appear tangent are tangent
Answer:
17. C 60°
18. D 121°
Step-by-step explanation:
The external angle is half the difference of the intercepted arcs.
17. (161° -41°)/2 = 60°
__
18. (? -59°)/2 = 31°
? = 59° +2(31°) = 121°
External angle∠C of the given circle is 60°
The angle subtended by the arc VS is 121°
What is the formula for external angle made by extending two chords?External angle is half of the difference between angles subtended by arcs.
So in problem 17,
∠C = (161°-41°)/2 = 60°
In problem 18,
We got the external angle = 59°
Let us take the angle subtended by arc = x
so,
(x-59°)/2 = 31°
x = 121°
Therefore, External angle∠C of the given circle is 60°
The angle subtended by the arc VS is 121°
To get more about circles refer to the link,
brainly.com/question/25938845
An archer has $62 to spend on a new archery
set. A certain set containing a bow and three arrows costs $42. With the purchase of this set, he can purchase additional arrows for $4 per arrow. Use an inequality to find the maximum number of arrows he could obtain, including those with the set, for his $62.
Answer:
5 more arrows
Step-by-step explanation:
62 - 42 = 20 20 / 4 = 5
The archer can buy 5 more arrows.
Hope this helps! If it did, please give brainliest! It would help a lot! Thanks! :D
Rebecca buys some socks that cost $5 per pair and 2 t-shirts that cost $12 each. The cost of Rebecca’s total purchase is $39.
Answer:
3 pairs of socks
Step-by-step explanation:
2 shirts *12per shirt = $24 spent so far
$39 - $24 dollars spent so far = $15 dollars left
$15 dollars left/$5 per pair of socks = 3 pairs of socks.
An equation is formed of two equal expressions. The total number of socks that Rebecca bought is 3.
What is an equation?An equation is formed when two equal expressions are equated together with the help of an equal sign '='.
Let the number of pairs of socks that Rebecca bought be represented by x.
Given that Rebecca buys some socks that cost $5 per pair and 2 t-shirts that cost $12 each. Also, the total purchase value is $39. Therefore, we can write the equation as,
Purchase value of socks + Purchase value of t-shirts = Total purchase value
($5 × x) + ($12 × 2) = $39
5x + 24 = 39
5x = 39 - 24
5x = 15
x = 15/5
x = 3
Hence, the total number of socks that Rebecca bought is 3.
Learn more about Equation here:
https://brainly.com/question/14686792
#SPJ2
The hockey team won 60 out of the 80 games it played this year. What percent of the games did the team win?
What is the equation of the line that passes through the point (-2,-2) and has a
slope of 22
Answer:
y=22x+42.
Step-by-step explanation:
1. the common view of the required equation in slope-interception form is:
y=s*x+i, where s - slope, i - interception;
2 if according to the condition s=22, then the required equation is:
y=22x+i;
3. if according to the condition the required line passes through the (-2;-2), then it is possible to substitute its coordinates into the required equation and calculate the value of 'i':
-2=22*(-2)+i; ⇒ i=42;
4. if s=22, i=42, then the required line is:
y=22x+42.
please hepl please i want help
Answer:
19/35
Step-by-step explanation: 2/5=14/35 1/7=5/35 14/35+5/35=19/35
Answer:
[tex]\frac{19}{35}[/tex]
Step-by-step explanation:
in order to add fractions, they must have the same denominator.
to get the same denominator you can multiply both fractions to get the same number on the bottom
the LCD of 5 and 7 is 35 so you do
[tex]\frac{1}{7}[/tex] · [tex]\frac{5}{5}[/tex] which equals [tex]\frac{5}{35}[/tex]
and
[tex]\frac{2}{5}[/tex] · [tex]\frac{7}{7}[/tex] which equals [tex]\frac{14}{35}[/tex]
now you can add
[tex]\frac{5}{35} +\frac{14}{35} = \frac{19}{35}[/tex]
1. Laura buys a pack of 24 blueberry muffins that has a total
of 1,536 calories. What is her calorie intake, if she ate 3
muffins for breakfast?
Answer:
192
Step-by-step explanation:
you have divide 24 by 3 and once you get that you get 8 then you do the amount of calories divide by 8
Solve for b:19-b=31
Answer:
-12
Step-by-step explanation:
help and i give points
Answer:
Red flowers:
fraction: [tex]\frac{40}{100}[/tex]
decimal : 0.40
percent : 40%
ratio: 40:100
Orange flowers:
fraction: [tex]\frac{6}{100}[/tex]
decimal: 0.06
percent: 6%
ration: 6:100
Purple flowers:
fraction: [tex]\frac{47}{100}[/tex]
decimal: 0.47
percent: 47%
ratio: 47:100
Green flowers:
fraction: [tex]\frac{7}{100}[/tex]
decimal: 0.07
percent: 7%
ratio: 7:100
Factor out the GCF of the three terms, then complete the factorization of x^4+9x^3+14x^2
Answer:
2
Step-by-step explanation:
find the greatest common factor, and then it is x^2(x+2) (x+7)
Which is the smallest tow rope needed to pull an 8000 N pallet across a warehouse floor? Click the image to find the answer
10000 n
4000 n
24000 n
2700 n
Answer: force F = uN, u 0.34 and N = 8000 N also F = 2720 N, thus 4000 N is enough
It
Step-by-step explanation:
Answer:
10,000 i think....i hope this helps
Step-by-step explanation:
What is a negative number minus a negative number?
Answer:
[tex]-x-(-y) = y-x[/tex]
Step-by-step explanation:
lets say you have two negative numbers, -x and -y (x and y are positive).
[tex]-x-(-y) = y-x[/tex]
Your answer is a positive number.
The value, in dollars, of an antique has increased exponentially over x years as shown in the graph. Estimate the y-intercept of the function. What does the intercept represent in context? A. 1,000; the percent increase in value of the antique per year B. 1,000; the value of the antique at 0 years of age C. 1,000; the value of the antique at 1 year of age D. 1,000; the amount the value of the antique increases per year
Answer:
The answer is C.
Step-by-step explanation:
I just did the test and the answer was C
The intercept is 1,000; the value of the antique at 1 year of age.
What is slope?A line's slope is determined by how its y coordinate changes in relation to how its x coordinate changes. y and x are the net changes in the y and x coordinates, respectively. Therefore, it is possible to write the
change in y coordinate with respect to the change in x coordinate as,
m = Δy/Δx
where, m is the slope
Given:
Let us take two points from the graph (0, 1000) and (35, 4000)
Now, slope= ( 4000- 1000)/(35- 0)
= 3000/35
= 600/7
Now, slope- intercept form
y- 1000= 600/7 ( x- 0)
y- 1000 = 600/7 x
y= 600/7x + 1000
Hence, the intercept is 1,000; the value of the antique at 1 year of age.
Learn more about slope here:
https://brainly.com/question/3605446
#SPJ3
helpppppp ill give brainliest answer if you know
Answer: 522.67 mm^3
Step-by-step explanation:
use formula
NEED ANSWER QUICK!!
In the diagram, the measure of angle 3 is 89°, and the measure of angle 6 is 88°.
A transversal intersects 2 lines to form 8 angles. Clockwise from the top left, the angles are 1, 2, 3, 4; 5, 6, 7, 8.
What is the measure of angle 4?
88°
89°
91°
92°
9514 1404 393
Answer:
(c) 91°
Step-by-step explanation:
Based on your description, it appears that angles 3 and 4 form a linear pair. This means angle 4 is the supplement to angle 3:
angle 4 = 180° -89°
angle 4 = 91°
Answer:
91°
Step-by-step explanation:
40 QUESTIONS FOR JUST ONE QUESTION :) QUESTION 6
Answer: Credit to work in process invetory-assembly
Answer:
its C because it makes the most sense "Credit to work in process invetory-assembly."
Step-by-step explanation:
a) The mean age of graduate students at a University is at most 31 y ears with a standard deviation of two years. A random sample of 15 graduate students is taken. The sample mean is 32 years and the sample standard deviation is three years. Are the data significant at the 1% level? The p-value is 0.0264. State the null and alternative hypotheses and interpret the p-value. Write information given with correct symbols. Hypothesis interpret the p-value. b) A bottle of water is labeled as containing 16 fluid ounces of water. You believe it is less than that. What type of test would you use? c) Assume the null hypothesis states that the mean is at most 12. Is this a left-tailed, right-tailed, or two-tailed test? d) What should you do if α = p-value?
Answer:
A.)
H0: μ ≤ 31
H1: μ > 31
B.)
H0: μ ≥ 16
H1: μ < 16
C.)
Right tailed test
D.)
If Pvalue is less than or equal to α ; we reject the Null
Step-by-step explanation:
The significance level , α = 0.01
The Pvalue = 0.0264
The decision region :
Reject the null if :
Pvalue < α
0.0264 > 0.01
Since Pvalue is greater than α ; then, we fail to reject the Null ;
Then there is no significant evidence that the mean graduate age is more Than 31.
B.)
H0: μ ≥ 16
H1: μ < 16
Null Fluid contains 16
Alternative hypothesis, fluid contains less than 16
One sample t - test
C.)
Null hypothesis :
H0 : μ ≤ 12
. The direction of the sign in the alternative hypothesis signifies the type of test or tht opposite direction of the sign in the null hypothesis.
Hence, this is a right tailed test ; Alternative hypothesis, H1 : μ > 12
d.)
If Pvalue is less than or equal to α ; we reject the Null.
convertir 5000 cm a km
Answer:
0.05 kilometer is the answer
Step-by-step explanation:
hope this answer may help you
besties help thanks <3
Answer:
2 = 70
4 = 140
6 = 210
8 = 280
Step-by-step explanation:
Two angles are supplementary. If one angle is 45° less than twice of the other angle, find the two angles.
Answer:
we will call the two angles a and b
a = 105
b = 75
Step-by-step explanation:
Supplementary means the two angles add up to 180 degrees. Now this turns into a system of equations problem. let's call the two angles a and b.
Lets say angle a is 45 degrees less than twice the other angle. that means a = 2b - 45. The first part told us a + b = 180
a + b = 180
a = 2b - 45
Now this is actually super easy to do. Normally you would have to do algebra to one of the two equations so there is one variable by itself. the second equation already has that.
now look at the other equation. instead of a though make a = 2b - 45
a + b = 180
2b - 45 + b = 180
Now use algebra to solve for b
2b - 45 + b = 180
b = 75
Now, go back to the first two equations. put 75 in for b for either one of them and you will get the answer to a.
a + 75 = 180
a = 105
or
a = 2*75 - 45
a = 105
Now we can check. a=105 and b = 75
do both add up to 180? yep. is a 45 less than twice b? or using numbers, is 105 45 less than twice 75? well twice 75 is 150. and 105 is 45 less than that, so yep!
Let me know if there was anything you didn't get. Also you could totally have started with the other equation first and got a = 180 - b or b = 180 - a and gotten the same answer.