Consider the following simple regression model: y = 0 + 1 x 1 + u. In order to obtain consistent estimators of 0 and 1, when x and u are correlated, a new variable z is introduced into the model which satisfies the following two conditions: Cov( z, x) 0 and Cov ( z, u) = 0. The variable z is called a(n) _____ variable. 答案选项组 dummy instrumental lagged dependent random
Answer:
Instrumental variable
Step-by-step explanation:
cov(z,u) shows that the instrumental variable is exogenous. An instrumental variable can also be regarded as a third variable, It is included in the model if you have an issue of endogeneity in your regression model. An endogeneity problem arises if there are other variables are being influenced by other independent variable in the same regression model. we use z to account for these behaviours in the model. this variable controls for measurement errors as well as confounding errors.
Solve the simultaneous equation:
8d - 4e = 28
6d + 3e = 3
Answer: d=2 and e= -3
Step-by-step explanation:
(8d-4e=28)*3 => 24d-12e=84
(6d+3e=3)*4 => 24d+12e=12
24d+24d-12e+12e=84+12
=> 48d=96
=> d=2
d=2 => 8*2-4e=28
=> e= -3
Find the exact surface area of the figure.
A parabola can be represented by the equation x2 = –20y.
What are the coordinates of the focus of the parabola?
(–5,0)
(5,0)
(0,5)
(0,–5)
Answer:
[tex] {x}^{2} = - 20y \\ y = - \frac{1}{20} {x}^{2} \\ { \tt{y = 4a {x}^{2} }} \\ a = - \frac{1}{5} \\ \\ { \tt{focus = (0, \: - 5)}}[/tex]
The requried coordinates of the focus of the parabola x² = -20y are (0, -2.5), which corresponds to the option (0, -5).
What is a parabola?A parabola is a cross-section cut out of the cone and represented by an equation y = 4ax².
The standard form of the equation of a parabola is (y - k) = (1 / 4p)(x - h)², where (h, k) is the vertex and p is the distance from the vertex to the focus. We can convert the given equation x² = -20y into this standard form by completing the square:
x² = -20y
x² / (-20) = y
x² / (-20) + 0 = y + 0
(x - 0)² = -20(y - 0)
Comparing this equation to the standard form, we can see that the vertex is at (h, k) = (0, 0), and that 4p = -20, so p = -5/2.
Since the focus is a distance of p below the vertex, the focus is at (h, k - p) = (0, -5/2), which is the same as (0, -2.5).
Therefore, the coordinates of the focus of the parabola x² = -20y are (0, -2.5), which corresponds to the option (0, -5).
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What is the answer of
Step-by-step explanation:
here is the answer babe. Feel free to ask for more
Answer: - 1.
Step-by-step explanation:
[tex]\frac{\dfrac{x+y}{x-y} }{\dfrac{y+x}{y-x} } =\dfrac{x+y}{x-y} \div \dfrac{y+x}{y-x}\\\\{\: \: \: \: \: \: \: \: \: \: \: \: \: } = \dfrac{x+y}{x-y} \times \dfrac{y-x}{y+x}\\\\{\: \: \: \: \: \: \: \: \: \: \: \: \: } = \dfrac{x+y}{x-y} \times \dfrac{-(x-y)}{x+y}\\\\{\: \: \: \: \: \: \: \: \: \: \: \: \: } = \dfrac{-(x+y)(x-y)}{(x-y)(x+y)} \\\\{\: \: \: \: \: \: \: \: \: \: \: \: \: } = -1[/tex]
60 PTS PLS ANSWER WILL AWARD BRAINLIEST ASAP
Answer:
9. a) 180 - (55+90) = a
b) a=35 degrees
10. a) 2w + 3w + 40 = 180
b) w=28
c) 2w=56 3w=84
Step-by-step explanation:
Answer:
the person above is 100% right trust me :)
Step-by-step explanation:
Select a figure from the options which will replace the(?) as established by the problem figure
Answer:
a) is the correct answer.
The probability that Andrew has heart disease The two events are independent, so you need to find
the product of their probabilities: 0.9 x 0.75 = 0.675. Enter the
correct answer The probability that Andrew has heart disease
Answer:
correct bayan HAHAHAHAHAHA
if r=1 and 0=5pi/6 what is the approximate arc length?
Answer:
B. 2.618 units
Step-by-step explanation:
the arc length = (5π/6) / 2π × 2×3.14×1
= 5/12 × 6.28
= 31.4/ 12
= 2.618 units
The arc length is = 2.618 units
what is arc length of a circle?Arc measure is a degree measurement, equal to the central angle that forms the intercepted arc. Arc length is a fraction of the circumference of the circle.
Given : r=1, [tex]\theta[/tex]= 5π/6
Now, arc length
= [tex]\theta[/tex]/ 2π * 2πr
= (5π/6) / 2π × 2×3.14×1
= 5/12 × 6.28
= 31.4/ 12
= 2.618 units
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Don’t need to send the math or anything just need the answer will give brainliest!!!
Answer:
The answer is D, Katie paid $40 for 4 hours
Step-by-step explanation:
If Rita pays $35 for 3 hours and Luna pays $45 for 5 hours
Just do 35 + 5 = 40
You get 40, so,
Katie paid $40 for 4 hours
Oh, i legit didnt see that "Dont need to send the math"
my bad, srry.
Round to 3 SF
0.0692494
rounding 0.0692494 to 3SF is 0.069
Please help thanks! Please put answer is square millimeters
Answer: 239
Step-by-step explanation:
3x7=21
(16+5)x16=336, 336/2=168
5x10=50
add them all together to get 239
hope this helps!
By visual inspection determine the best-fitting regression model for the data plot below
Answer:
Exponential
Step-by-step explanation:
By visual inspection the graph generated by the points plotted is an exponential graph as the graph curves upward. The graph is also continous and differs from either a decreasing or increasing Linear graph, which shows a straight best of fit pattern. Hence, the graph most closely represents an exponential graph from visual examination.
The best-fitting regression model for the considered data plot is given by:
Option A: Exponential.
What is fitting of curve for a data plot?When the data shows some trend, either linear (making a line), or non-linear (a predictable curve), we fit a mathematical curve on that data set, as a representative of the pattern in that data set, to predict the output based on the inputs.
The considered plot is not forming a straight line(so no linear fitting), but we can see that a smooth curve can be fitted in the considered data. Since the exponential functions' graph approximately goes the same way (for positive exponent, and increasing value of output).
Thus, the best-fitting regression model for the considered data plot is given by: Option A: Exponential.
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A ball is thrown from an initial height of 4 feet with an initial upward velocity of 30 feet per second. Find all values of t for which the ball's height is 17 feet.
Answer:
0.43 seconds
Step-by-step explanation:
Given Data
Initial height= 4feet
initial velocity u= 30ft per second
Final height = 17 feet
The distance travelled is the
Final-initial height
=17-4
=13ft
Hence the time taken is calculated using the expression below
Speed= distance/time
30=13/t
t= 13/30
t= 0.43 seconds
Hence the time taken is 0.43 seconds
8f(x)=x
2
+6x+8f, left parenthesis, x, right parenthesis, equals, x, squared, plus, 6, x, plus, 8
1) What are the zeros of the function?
Write the smaller xxx first, and the larger xxx second.
\text{smaller }x=smaller x=start text, s, m, a, l, l, e, r, space, end text, x, equals
\text{larger }x=larger x=start text, l, a, r, g, e, r, space, end text, x, equals
2) What is the vertex of the parabola?
Answer:
-2 and -4
Step-by-step explanation:
Given the function f(x) = x² + 6x + 8
If f(x) = 0
x² + 6x + 8 = 0
Factorize
x² + 4x + 2x+ 8 = 0
x(x+4)+2(x+4) = 0
(x+2)(x+4) = 0
x+2 = 0 and x+4 = 0
x = -2 and -4
Hence the zero of the function is -2 and -4
Which answer choice shows a solution set in which all values, when input for x, will be true?
12−(x+2)>2
Answer:
It would be x < 8
Step-by-step explanation:
The interval notation is (-∞, 8)
Hope this helps:)
Please can someone solve some questions on similar triangles ASAP.
Answer:
post the question i can do it
Step-by-step explanation:
if (x+y , 2x-3) = (5,3) find the value of x and y. plz answer ASAP!!!
Answer:
x=3
y=0
Step-by-step explanation:
2x-3=3
2x=6
x=3
x+y=3
3+y=3
y=0
Answer:
ans: x= 3 and y= 2
Step-by-step explanation:
equating corresponding order pair,
x + y = 5 and
2x-3 = 3
so x=6/2 I.e
x= 3
putting x in
x + y = 5
y = 5- 3
y = 2
I will give BRAINLIEST to the correct answer
Find the measure of angle 6.
Answer:
m∠6 = 116°
Step-by-step explanation:
first find x:
7x - 17 = 2x + 78
subtract 2x from both sides: 5x - 17 = 78
add 17 to both sides: 5x = 95
divide by 5: x = 19
plug x into 7x - 17
7(19) - 17 = 116
∠6 and 7x - 17 are vertical angles and therefore congruent, so m∠6 also = 116°
The container of orange juice held 53 cups of juice. If a serving of orange juice is ã of a cup of orange juice, to the
nearest whole serving, how many servings were in the container?
05 servings
O 6 servings
15 servings
19 servings
Mark this and return
Save and Exit
Next
Submit
Answer:
5 servings = 265 cups of orange juices
5 servings = 318 cups of orange juices
5 servings = 795 cups of orange juices
5 servings = 1,007 cups of orange juices
Step-by-step explanation:
Given:
1 serving contain = 53 cups of orange juices
Find:
Serving in;
5 servings
6 servings
15 servings
19 servings
Computation:
5 servings = 53 x 5
5 servings = 265 cups of orange juices
5 servings = 53 x 6
5 servings = 318 cups of orange juices
5 servings = 53 x 15
5 servings = 795 cups of orange juices
5 servings = 53 x 19
5 servings = 1,007 cups of orange juices
203 cm
196 cm
Question 1:
The formula to calculate the perimeter of the banner is
(a) 2 (1+ b)
(b) 2xrh + 2A
(c) a + (21 + b)
(d) 2 (1 + b) + ar
Answer:
πr + (2l + b)
Step-by-step explanation:
The figure is a composite figure, consisting of a semicircle and a rectangle :
The perimeter of a rectangle is the sum of the sides ;
Perimeter of semicircle is the 2πr/2 (Circumference / 2)
For the triangle, we take the sum of 3 sides ;
Length + length + breadth = 2l + b
Hence, the perimeter is :
2πr/2 + 2l + b
πr + (2l + b)
The rule g = b + 3 expresses the relationship between the
number of girls g and the number of boys b in a classroom.
Rewrite this rule another way.
Answer:
g = 3 + b
b + 3 = g
3 + b = g
Step-by-step explanation:
Answer:
[see below]
Step-by-step explanation:
Rewriting the rule so 'b' would be the subject:
[tex]g = b + 3\\\\g - 3 = b + 3-3\\\\g-3=b\\\\\boxed{b=g-3}[/tex]
Hope this helps.
A triangle is shown. What is X?
Answer: 44º
Step-by-step explanation:
Hi there! To start out, disregard Y and Z, as they are just there to trip you up.
Use the Triangle Sum Theorem to find out the question! This theory states that all angles in a triangle add up to 180 degrees. So, just set up an equation, like the one down below!
82+54+X=180
Then, add the whole numbers!
136+X=180
Then isolate X by using inverse operations!
136+X-136=180-136
Then your answer is there!
X=44
If you have any follow up questions, please let me know! Have a nice day
If a salon charges rupees 99 for a haircut, how much money did the salon earn over the week?
Answer:
5940 rupees
Step-by-step explanation:
99 multiplied by 29×5 is 5940
Answer:
[tex]\text{(b) }[/tex] ₹[tex]5,940[/tex]
Step-by-step explanation:
Each pair of scissors on the chart represents 5 haircuts, as indicated by the key. There are 2 scissors on Saturday and 10 scissors on Sunday, hence a total of 12 scissors over the weekend. Therefore, there were [tex]12\cdot 5=60[/tex] haircuts over the weekend.
Since the salon charges 99 rupees per cut, they made a total of [tex]99\cdot 60=\boxed{5,940}[/tex] rupees over the weekend.
If y is 22.6 and c is 28.2, find b, rounded to the nearest tenth.
How much is -1/4 is 1 1/3?
Answer:
4 option
Step-by-step explanation:
2 extra large chocolate shakes contain 85 ounces of ice cream. How many ounces of ice cream are there in 12 extra large chocolate shakes?
plz show work
Answer:
It will be 1020
Step-by-step explanation:
2 extra large = 85 ounces
multiply by 6 to get to 12 cups
85*12=1020
Find the missing segment
Answer:
The unknown side is 140
Step-by-step explanation:
Let the unknown side be x
Using ratios
90 90+36
------ = -----------
x x+56
90 126
------ = -----------
x x+56
Using cross products
90(x+56) = 126x
Distribute
90x+5040 = 126x
Subtract 90x
5040 = 36x
Divide by 36
140 =x
Put these numbers in order from greatest to least.
0.24,0.73,1/4, and 3/4
Answer:
3/4, 0.73, 1/4, 0.24
Step-by-step explanation:
1/4=25/100=0.25
3/4=75/100=0.75
Find the value of x in the triangle shown below
Answer:
x = 48°
Step-by-step explanation:
Two sides of the triangle are equal, both 7, Then the 2 base angles are congruent, both 66°
The sum of the 3 angles in the triangle sum to 180° , so
x = 180° - (66 + 66) = 180° - 132° = 48°
Answer:
[tex]{ \tt{x + 66 + 66 = 180}} \\ x = 48 \degree \\ \\ { \boxed{ \bf{or : }}} \\ { \bf{ from \:lamis \: theorem : }} \\ { \tt{ \frac{5.7}{ \sin(x) } = \frac{7}{ \sin(66 \degree) } }} \\ \\ { \tt{x = { \sin }^{ - 1}( \frac{5.7 \times \sin(66 \degree) }{7} ) }} \\ x = 48 \degree[/tex]
