Solution :
a). [tex]$\text{Var} (X|Y) =E ((X-E(X|Y))^2 |Y)$[/tex]
Now, if X = Y, then :
[tex]P(X|Y)=\left\{\begin{matrix} 1,& \text{if } x=y \\ 0, & \text{otherwise }\end{matrix}\right.[/tex]
Then, E[X|Y] = x = y
So, [tex]$\text{Var} (X|Y) =E((X-X)^2 |Y)$[/tex]
[tex]$=E(0|Y)$[/tex]
= 0
Therefore, this statement is TRUE.
b). If X = Y , then Var (X) = Var (Y)
And as Var (X|Y) = 0, so Var (X|Y) ≠ Var (X), except when all the elements of Y are same.
So this statement is FALSE.
c). As defined earlier,
[tex]$\text{Var} (X|Y) =E ((X-E(X|Y))^2 |Y=y)$[/tex]
So, this statement is also TRUE.
d). The statement is TRUE because [tex]$\text{Var} (X|Y) =E ((X-E(X|Y))^2 |Y=y)$[/tex].
e). FALSE
Because, [tex]$\text{Var} (X|Y) =E ((X-E(X|Y=y))^2 |Y=y)$[/tex]
write the following statement in symbolic mongo are delicious but expensive .
Step-by-step explanation:
let a=mangoes are delicious
b=mangoes are expensive
the symbolic form is a^b
In 2006, there were 160 teachers in College A, and three fourth of them had their own vehicles. In 2007, 20 new teachers came to the school and 6 of them had own vehicles. Calculate the percentage increase in the numbers of teacher who had own vehicles.
Answer: 5%
Step-by-step explanation:
In 2006, there were 160 teachers in College A, and ¾ of them had their own vehicles, the number of people who had their own vehicles will be:
= 3/4 × 160
= 120
In 2007, 20 new teachers came to the school and 6 of them had own vehicles. This means the number if people with vehicles will be:
= 120 + 6
= 126
The percentage increase will be:
= Increase / Old vehicle owners × 100
= 6/120 × 100
= 1/20 × 100
= 5%
The Percentage increase is 5%.
2) There are 40 boys and 60 girls in a class of students. What is the ratio of girls to students
Answer:
60:100, 6/10, 3/5, 6 to 10, etc.
Step-by-step explanation:
You take the number of girls over total students which is boys + girls. Since there's 40 boys and 60 girls, it's 60 girls to 100 students which can be written in several ways.
Answer:
60:100 / 3:5
Step-by-step explanation:
You first add the total number of students which is (40boys + 60girls) which gives us 100 students.
Then arrange the ratio of girls to students as per the question that is 60:100, reduce it to its lowest term that is dividing the ratio by 20, and finally got 3:5
Please help !! Only answer if 100% it is correct :)
Answer:
F(x) moved right 2 units to become G(X).
According to graph transformations, that means G(X) = F(X - 2) = [tex](X-2)^{3}[/tex].
I think that's how you do it :\
The diagram below shows rectangle ABC is a midtsin of
BC, such that D,E and F are on the same line API AD
i = 53, 13" BE-sm
and DE 2 EF
84
2176
F
with reasons
3.1 Prove
AB - BF
3.2. Calculate AD
3.3 Complece. In are rigter angled A BEF, son 53, 13" - BE
Answer:
4x2+3=
Step-by-step explanation:
find the least common multiple of two two-digit numbers. SHOW WORK
Answer:
The LCM of 20 and 30 is 60.
Step-by-step explanation:
LCM means the least common multiple.
The LCM of two numbers means the least multiple both numbers share.
Use the listing method:
Multiples of 20:
20, 40, 60, 80, 100, ......
Multiples of 30:
30, 60, 90, 120, 150, ...
The LCM is 60 because that is the least common multiple 20 and 30 have.
Hope this helps
Cross out three digits in the number 51489704 so that the resulting number is divisible by 45. What number is left?
The factors of 45 are 9 and 5.
A number divisible by 45 needs to be divisible by both 9 and 5.
For a number to be divisible by 9 the sum of the digits must also be divisible by 9 and the number needs to end with either a 0 or a 5 to be divisible by 5.
This means the number needs to end with the 0 so cross out the last number (4)
Now find a sum of 5 remaining numbers divisible by 9.
5 + 1 + 4 + 8 + 0 = 18 which is divisible by 9
Cross out 9,7 and the last number 4 to get the number: 51480
Given the points (-7, -1) and (8, 5) find the slope.
Answer:
(-7, -1) =(x1,y1)
(8, 5)=(x2,y2)
now
[tex]slope (m) = \frac{y2 - y1}{x2 - x1} [/tex]
[tex]or = \frac{5 - ( - 1)}{8 - ( - 7)} [/tex]
[tex]or = \frac{5 + 1} {8 + 7} [/tex]
[tex]or = \frac{6}{15} [/tex]
[tex]or = \frac{2}{5} [/tex]
Step-by-step explanation:
Explanation is in the attachmenthope it is helpful to you ☺️
The width of a rectangle is 2 cm less than its length. The perimeter is 52 cm. The length is:
14 cm.
12 cm.
9 cm.
None of these choices are correct.
Answer: 14 cm
Step-by-step explanation:
Rectangle:
Length = xWidth = x - 2x + x + (x - 2) + (x - 2) = 52
2x + 2(x - 2) = 52
2x + 2x - 4 = 52
4x = 52 + 4
4x = 56
x = 14
Suppose a large shipment of televisions contained 9% defectives. If a sample of size 393 is selected, what is the probability that the sample proportion will differ from the population proportion by less than 3%
Answer:
0.9624 = 96.24% probability that the sample proportion will differ from the population proportion by less than 3%
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
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 z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Suppose a large shipment of televisions contained 9% defectives
This means that [tex]p = 0.09[/tex]
Sample of size 393
This means that [tex]n = 393[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.09[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.09*0.91}{393}} = 0.0144[/tex]
What is the probability that the sample proportion will differ from the population proportion by less than 3%?
Proportion between 0.09 - 0.03 = 0.06 and 0.09 + 0.03 = 0.12, which is the p-value of Z when X = 0.12 subtracted by the p-value of Z when X = 0.06.
X = 0.12
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.12 - 0.09}{0.0144}[/tex]
[tex]Z = 2.08[/tex]
[tex]Z = 2.08[/tex] has a p-value of 0.9812
X = 0.06
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.06 - 0.09}{0.0144}[/tex]
[tex]Z = -2.08[/tex]
[tex]Z = -2.08[/tex] has a p-value of 0.0188
0.9812 - 0.0188 = 0.9624
0.9624 = 96.24% probability that the sample proportion will differ from the population proportion by less than 3%
in a board game you must roll two 6-sided number cubes. you can only start the game if you roll a 3on at least one of the number cubes.
Answer:
[tex]1-(5/6)^2[/tex]
31% chance
1 in 3.272727273 rolls
Step-by-step explanation:
write an equation rectangular room 3 meters longer than it is wide and its perimeter is 18 meters
width = x
length = 3 + x
perimeter = x + x + ( 3 + x ) + (3+x)
18 = x + x + ( 3 + x ) + (3+x)
x + x + ( 3 + x ) + (3+x) = 18
6 + 4x = 18
4x = 12
x = 3
Michael was 1.0 metres tall, and could
only reach up to the 1st floor lift button. .
From the 1st floor, he had to walk up 100
steps to reach the 6th floor.
Vinh was 1.4 metres tall, and could reach
the 5th floor button. He had to walk up
20 steps to reach the 6th floor.
Lucy was 1.1 metres tall. To reach the
6th floor, how many steps did she have to
walk up?
Answer:
Lucy must walk up 80 steps to reach the 6th floor.
Step-by-step explanation:
Since Michael was 1.0 meters tall, and could only reach up to the 1st floor lift button, and from the 1st floor, he had to walk up 100 steps to reach the 6th floor; while Vinh was 1.4 meters tall, and could reach the 5th floor button, and he had to walk up 20 steps to reach the 6th floor; If Lucy was 1.1 meters tall, to determine how many steps did she have to walk up to reach the 6th floor, the following calculation must be performed:
1 = 100
1.4 = 20
1.4 - 1 = 100 - 20
0.4 = 80
0.1 = X
0.1 x 80 / 0.4 = X
20 = X
100 - 20 = 80
Therefore, Lucy must walk up 80 steps to reach the 6th floor.
Someone please help me ASAP!
Answer:
The 3rd
Step-by-step explanation:
If x goes to infinity, f(x) goes to infinity too:
[tex]lim \: \frac{2 {x}^{2} }{3x - 1} = lim \frac{2x}{3 - \frac{1}{x} } = \frac{ 2 \times \infty }{3 - 0} = \infty [/tex]
Donald and Sara are surveying their neighbors about the community playground. Their questions, written on the survey, are below:
Donald: How many times do you visit the playground in a month?
Sara: Did you visit the playground this month?
Who wrote a statistical question and why?
Sara, because there will be variability in the responses collected
Donald, because every neighbor can give a different answer
Sara, because there can be only one answer to the question
Donald, because every neighbor will give the same answer
Answer:
B
Step-by-step explanation: Because Donald asks a more broad and open question which people could give different answers too
When 4 times a positive number is subtracted from the square of the number, the result is 5. Find the number.
Answer:
5
Step-by-step explanation:
x² - 4x = 5
x² - 4x - 5 = 0
the solution of a quadratic equation is
x = (-b ± sqrt(b² - 4ac))/(2a)
a = 1
b = -4
c = -5
x = (4 ± sqrt(16 + 20))/2 = (4 ± sqrt(36))/2
x1 = (4 + 6)/2 = 5
x2 = (4 - 6)/2 = -1
since we are looking only for a positive number, x=5 is the answer.
Factor 2x2+25x+50. Rewrite the trinomial with the x-term expanded, using the two factors.
9514 1404 393
Answer:
rewrite: 2x^2 +5x +20x +50factored: (x +10)(2x +5)Step-by-step explanation:
I find this approach the most straightforward of the various ways that trinomial factoring is explained or diagramed.
You want two factors of "ac" that have a total of "b". Here, that means you want factors of 2·50 = 100 that have a total of 25. It is helpful to know your times tables.
100 = 1·100 = 2·50 = 4·25 = 5·20 = 10·10
The sums of these factor pairs are 101, 52, 29, 25, and 20. We want the pair with a sum of 25, so that's 5 and 20.
The trinomial can be rewritten using these factors as ...
2x^2 +5x +20x +50
Then it can be factored by grouping consecutive pairs:
(2x^2 +5x) +(20x +50) = x(2x +5) +10(2x +5) = (x +10)(2x +5)
_____
Additional comment
It doesn't matter which of the factors of the pair you write first. If our rewrite were ...
2x^2 +20x +5x +50
Then the grouping and factoring would be (2x^2 +20x) +(5x +50)
= 2x(x +10) +5(x +10) = (2x +5)(x +10) . . . . . same factoring
Convert the following to a simplified fraction. Show all your work.
Answer:
11/6
Step-by-step explanation:
In parallelogram ABCD, line AC is congruent to line BD. Is ABCD a rectangle?
A. Yes
B. No
C. Cannot be determined
9514 1404 393
Answer:
A. yes
Step-by-step explanation:
The diagonals of a rectangle are congruent and bisect each other.
The diagonals of a parallelogram bisect each other. If they are also congruent, then the parallelogram is a rectangle.
Answer:
Yes.
Step-by-step explanation:
Press option yes
Evaluate for x=2 and y=3: x^2y^-3/x^-1y
Answer:
8/81
Step-by-step explanation:
It's most efficient to simplify the quotient algebraically before inserting the values of the variables x and y.
The given expression reduces to x³ / y^4.
Substituting 2 for x and 3 for y, we get:
(2)³ 8
--------- = ---------- (Agrees with first given possible answer)
(3)^4 81
Find the third term of a geometric progression if the sum of the first three terms is equal to 12, and the sum of the first six terms is equal to (−84).
Given:
The sum of the first three terms = 12
The sum of the first six terms = (−84).
To find:
The third term of a geometric progression.
Solution:
The sum of first n term of a geometric progression is:
[tex]S_n=\dfrac{a(r^n-1)}{r-1}[/tex]
Where, a is the first term and r is the common ratio.
The sum of the first three terms is equal to 12, and the sum of the first six terms is equal to (−84).
[tex]\dfrac{a(r^3-1)}{r-1}=12[/tex] ...(i)
[tex]\dfrac{a(r^6-1)}{r-1}=-84[/tex] ...(ii)
Divide (ii) by (i), we get
[tex]\dfrac{r^6-1}{r^3-1}=\dfrac{-84}{12}[/tex]
[tex]\dfrac{(r^3-1)(r^3+1)}{r^3-1}=-7[/tex]
[tex]r^3+1=-7[/tex]
[tex]r^3=-7-1[/tex]
[tex]r^3=-8[/tex]
Taking cube root on both sides, we get
[tex]r=-2[/tex]
Putting [tex]r=-2[/tex] in (i), we get
[tex]\dfrac{a((-2)^3-1)}{(-2)-1}=12[/tex]
[tex]\dfrac{a(-8-1)}{-3}=12[/tex]
[tex]\dfrac{-9a}{-3}=12[/tex]
[tex]3a=12[/tex]
Divide both sides by 3.
[tex]a=4[/tex]
The nth term of a geometric progression is:
[tex]a_n=ar^{n-1}[/tex]
Where, a is the first term and r is the common ratio.
Putting [tex]n=3,a=4,r=-2[/tex] in the above formula, we get
[tex]a_3=4(-2)^{3-1}[/tex]
[tex]a_3=4(-2)^{2}[/tex]
[tex]a_3=4(4)[/tex]
[tex]a_3=16[/tex]
Therefore, the third term of the geometric progression is 16.
What is the minimum of y=1/3 x^2 + 2x + 5
Answer:
min at x = -3
Step-by-step explanation:
steps are in the pic above.
a circle has a radius that is 4 centimeters long. if a central angle has a measure of 3 radiants, what is the length of the arc that corresponds to the angle ?
A. 12 centimeters
B. 4 centimeters
C. 3 centimeters
D. 7 centimeters
Answer:
A number is right 12 centimetres
Drag the tiles to the correct boxes to complete the pairs.
Match each division of rational expressions with its quotient.
Answer:
Step-by-step explanation:
Um where is the diagrahm
if triangle TAN has vertices T(0, 2), A(-1,3), and N(-2,-4), which of the following coordinates is N' of the dilation from the origin using the scale factor 3?
Answer:
(-6,-12)
Step-by-step explanation:
A dilation makes a figure gets bigger so just multiply 3 to point N to find N prime.
[tex] - 2 \times 3 = - 6[/tex]
[tex] - 4 \times 3 = - 12[/tex]
So our new coordinates is
(-6,-12)
Answer:
(-6,-12)
Step-by-step explanation:
A dilation makes a figure gets bigger so just multiply 3 to point N to find N prime.
So our new coordinates is
(-6,-12)
Step-by-step explanation:
Use the arithmetic progression formula to find the sum of integers from 75 to 100.75,76,77....99,100.
Answer:
The sum is 2275
Step-by-step explanation:
Given
[tex]75,76,77....99,100[/tex]
Required
The sum
Using arithmetic progression, we have:
[tex]S_n = \frac{n}{2}(T_1 + T_n)[/tex]
Where:
[tex]T_1 = 75[/tex] --- first term
[tex]T_n = 100[/tex] --- last term
[tex]n = T_n - T_1 + 1[/tex]
[tex]n = 100 - 75 + 1 = 26[/tex]
So, we have:
[tex]S_n = \frac{n}{2}(T_1 + T_n)[/tex]
[tex]S_n = \frac{26}{2}*(75 + 100)[/tex]
[tex]S_n = 13*175[/tex]
[tex]S_n = 2275[/tex]
Which function has the following characteristics?
- A vertical asymptote at x=3
- A horizontal asymptote at y=2
- Domain: {x ≠ ±3}
A. y= (2x-8) / (x-3)
B. y= (2x^2 - 8) / (x^2 - 9)
C. y= (x^2 - 9) / (x^2 - 4)
D. y= (2x^2 - 18) / (x^2 - 4)
The function has the characteristics is (b) y= (2x^2 - 8) / (x^2 - 9)
How to determine the function?The features are given as:
A vertical asymptote at x=3A horizontal asymptote at y=2Domain: {x ≠ ±3}The function that has the above features is (b).
This is proved as follows:
y= (2x^2 - 8) / (x^2 - 9)
Set the denominator not equal to 0, to determine the domain
x^2 - 9 ≠ 0
Add 9 to both sides
x^2 ≠ 9
Take the square roots
x ≠ ±3 --- domain
Replace ≠ with =
x = ±3 --- vertical asymptote
Set the numerator to 0
2x^2 - 8 = 0
Divide through by 2
x^2 - 4 = 0
This gives
x^2 = 4
Take the square roots
x = 2 ---- horizontal asymptote
Hence, the function has the characteristics is (b) y= (2x^2 - 8) / (x^2 - 9)
Read more about functions at:
https://brainly.com/question/4138300
#SPJ1
(x-5)(X+12)=-70
[tex](x - 5)(x + 12) = - 70[/tex]
Answer:
[tex]x = - 2[/tex]
[tex]x = - 5[/tex]
Step-by-step explanation:
Give
[tex](x - 5)(x + 12)[/tex]
Apply FOIL Method
[tex]x {}^{2} + 7x - 60 = - 70[/tex]
Add 70 on both sides
[tex] {x}^{2} + 7x + 10[/tex]
Factor
[tex](x + 2)(x + 5)[/tex]
So our roots are
x=-2
x=-5
Answer:
dtet
Step-by-step explanation:
dgbyn
need help now!!! Please and thanks
Answer:
the answer of r is 8 i hope it will help
Many electronics follow a failure rate described by an exponential probability density function (PDF). Solar panels are advertised to last 20 years or longer, but panels made in China are failing at a higher rate. The time-to-failure of this device is usually exponentially distributed with mean 13 years. What is the probability of failure in the first 5 years
Answer:
The right answer is "0.3193".
Step-by-step explanation:
According to the question,
Mean,
[tex]\frac{1}{\lambda} = 13[/tex]
[tex]\lambda = \frac{1}{13}[/tex]
As we know,
The cumulative distributive function will be:
⇒ [tex]1-e^{-\lambda x}[/tex]
hence,
In the first 5 years, the probability of failure will be:
⇒ [tex]P(X<5)=1-e^{-\lambda\times 5}[/tex]
[tex]=1-e^{-(\frac{1}{13} )\times 5}[/tex]
[tex]=1-e^(-\frac{5}{13})[/tex]
[tex]=1-0.6807[/tex]
[tex]=0.3193[/tex]
