Here is the full question .
We are interested in finding an estimator for [tex]Var (X_i )[/tex] and propose to use :
[tex]\hat {V} = \bar {X}_n (1- \bar {X} )_n[/tex]
Now; we are interested in the basis of [tex]\hat V[/tex]
Compute :
[tex]E \ \ [ \bar V] - Var (X_i) =[/tex]
Using this; find an unbiased estimator [tex][ \bar V][/tex] for [tex]p(1-p) \ if \ n \geq 2[/tex]
Write [tex]bar \ x{_n} \ for \ X_n[/tex]
Answer:
Step-by-step explanation:
[tex]\bar X_n = \dfrac{1}{n} {\sum ^n _ {i=1} } \\ \\ E(X_i) = - \dfrac{1}{n=1} \sum p \dfrac{1}{n}*np = \mathbf{p}[/tex]
[tex]V(\bar X_n) = V ( \dfrac{1}{n_{i=1} } \sum ^n \ X_i )} = \dfrac{1}{n^2} \sum ^n_{i=1} Var (X_i) \\ \\ = \dfrac{1}{n^2} \ \sum ^n _{i=1} p(1-p) \\ \\ = \dfrac{1}{n^2}*np(1-p) \\ \\ = \dfrac{p(1-p)}{n}[/tex]
[tex]E( \bar X^2 _ n) = Var (\bar X_n) + [E(\bar X_n)]^2 \\ \\ = \dfrac{p(1-p)}{n}+ p \\ \\ = p^2 + \dfrac{p(1-p)}{n} \\ \\ \\ \hat V = \bar X_n (1- \bar X_n ) = \bar X_n - \bar X_n ^2 \\ \\ E [ \hat V] = E [ \bar X_n - \bar X_n^2] \\ \\ = E[\bar X_n ] - E [\bar X^2_n] \\ \\ = p-(p^2 + \dfrac{p(1-p)}{n}) \\ \\ = p-p^2 -\dfrac{p(1-p)}{n}[/tex]
[tex]=p(1-p)[1-\dfrac{1}{n}] = p(1-p)\dfrac{n-1}{n}[/tex]
[tex]Bias \ (\bar V ) = E ( \hat V) - Var (X_i) \\ \\ = p(1-p) [1-\dfrac{1}{n}] - p(1-p) \\ \\ - \dfrac{p(1-p)}{n}[/tex]
Thus; we have:
[tex]E [\hat V] = p(1-p ) \dfrac{n-1}{n}[/tex]
[tex]E [\dfrac{n}{n-1} \ \ \bar V] = p(1 -p)[/tex]
[tex]E [\dfrac{n}{n-1} \ \ \bar X_n (1- \bar X_n )] = p (1-p)[/tex]
Therefore;
[tex]\hat V ' = \dfrac{n}{n-1} \bar X_n (1- \bar X_n)[/tex]
[tex]\mathbf{ \hat V ' = \dfrac{n \bar X_n (1- \bar X_n)} {n-1}}[/tex]
What’s the correct answer for this?
Answer:
I think the answer is 282.6 but my answer is 297.33.
Answer:
the answer will be 282.6m^2
but that is not entirely correct
Step-by-step explanation:
Bob is a travel agent. He receives 7% commission when he books a cruise for a customer. How much commission will he receive for booking a $3,900 cruise?
Answer:
$273
Step-by-step explanation:
$3900= 100%
$39 = 1%
39(1%)*7= $273 (7%)
The commission will he received should be $273
Given that,
He receives 7% commission when he books a cruise for a customercalculation:= 7% of $3,900
= $273
Find out more information about percentage here:
https://brainly.com/question/26080842?referrer=searchResults
ACB = DCE
A = 3x-10, C = 45°, D = 2x+10
Please help confused
Answer:
x = 20
Step-by-step explanation:
The congruence statement tells you that angle A is congruent to angle D. (Both are listed first in the triangle names.) This means ...
∠A = ∠D
3x -10 = 2x +10
x = 20 . . . . . . . . . . add 10-2x to both sides
If 25% of a number is 100, what is the number?
OA.
50
B.
100
O C.
150
D.
200
o E.
400
Answer:
E. 400
Step-by-step explanation:
So this is how we set this up, and how we solve
[tex]0.25x=100\\x=100/0.25\\x=400[/tex]
Hope this helps!
So you are solving for circumference of a quarter circle: [tex]\frac{1}{4}2 \pi r[/tex]
r= 28
[tex]\pi=3.14[/tex]
[tex]\frac{1}{4}2(87.92)=\\43.96[/tex]
Express the following ratio in it’s simplest form.
25:30
Answer:
5/6
Step-by-step explanation:
Find the factor that divides both numbers...
25/5=5
30/5=6
5/6 is the simplified ratio
P.S. Please give me brainliest, i have only have two!
Answer:
1/3:1/4
Step-by-step explanation:
203/259
write in simplest form
2 hours to 45 seconds
Express ratio
15:1
simplest form
1/3:1/4
M5-3/2x less than or equal to 1/3
Answer: choice A
Step-by-step explanation:
by rearranging the initial inequality you’ll get
[tex]\frac{3}{2} x\leq 5-\frac{1}{3}[/tex]
which equals
[tex]\frac{3}{2} x\leq\frac{14}{3}[/tex]
then multiply both sides by 2/3
[tex]x\leq \frac{28}{9}[/tex]
Which geometric series converges?
Answer:
B
Step-by-step explanation:
Geometric series converge if |r| < 1.
A) r = 3
B) r = 1/2
C) r = -4
D) r = 2
Only B has |r| < 1.
The converging sequence of geometric progression is given by the relation A = 1 + 1/2 + 1/4 + 1/8 ... where the common ratio r = 1/2
What is Geometric Progression?A geometric progression is a sequence in which each term is derived by multiplying or dividing the preceding term by a fixed number called the common ratio.
The nth term of a GP is aₙ = arⁿ⁻¹
The general form of a GP is a, ar, ar2, ar3 and so on
Sum of first n terms of a GP is Sₙ = a(rⁿ-1) / ( r - 1 )
Given data ,
Let the geometric progression be represented as A
Now , the value of A is
A = 1 + 1/2 + 1/4 + 1/8 ...
Now , the common ratio r of the GP is
r = second term / first term
On simplifying , we get
r = ( 1/2 ) / 1
r = 1/2
So , when | r | < 1 , the GP is a converging series
Hence , the GP is converging series
To learn more about geometric progression click :
https://brainly.com/question/1522572
#SPJ7
Given that f(x)=x^2+4x-32f(x)=x
2 +4x−32 and g(x)=x-4g(x)=x−4, find (f+g)(x)(f+g)(x) and express the result in standard form.
Answer:
So your question was not very clear but with (f+g) im guessing thats f(x)+g(x)
So first we add them x^2+4x-32 + x-4 then we will get x^2 + 5x - 36
Then we need to multiply both
(x^2+5x-36)(x^2+5x-36)
=
(x^2+5x-36)^2
The only reason im not solving it out is because it yields large numbers and you might not understand.
is the square root of 5/8 rational or irrational
Answer:
the answer is square root 5 over 2 square root 2
Step-by-step explanation:
simplify (51/3)^3
i will give brainlist
Answer: D. 5
Step-by-step explanation:
Typically when you have exponents in a form like this, you would multiply 1/3 with 3 to get 1/3 * 3/1. The threes cancel out and you're left with an exponent of 1. And 5 to the 1 power is 5.
A company services home air conditioners. It is known that times for service calls follow a normal distribution with a mean of 75 minutes and a standard deviation of 15 minutes. A random sample of twelve service calls is taken. What is the probability that exactly eight of them take more than 93.6 minutes
Answer:
The probability that exactly eight of them take more than 93.6 minutes is 5.6015 [tex]\times 10^{-6}[/tex] .
Step-by-step explanation:
We are given that it is known that times for service calls follow a normal distribution with a mean of 75 minutes and a standard deviation of 15 minutes.
A random sample of twelve service calls is taken.
So, firstly we will find the probability that service calls take more than 93.6 minutes.
Let X = times for service calls.
So, X ~ Normal([tex]\mu=75,\sigma^{2} =15^{2}[/tex])
The z-score probability distribution for the normal distribution is given by;
Z = [tex]\frac{X-\mu}{\sigma}[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = mean time = 75 minutes
[tex]\sigma[/tex] = standard deviation = 15 minutes
Now, the probability that service calls take more than 93.6 minutes is given by = P(X > 93.6 minutes)
P(X > 93.6 min) = P( [tex]\frac{X-\mu}{\sigma}[/tex] > [tex]\frac{93.6-75}{15}[/tex] ) = P(Z > 1.24) = 1 - P(Z [tex]\leq[/tex] 1.24)
= 1 - 0.8925 = 0.1075
The above probability is calculated by looking at the value of x = 1.24 in the z table which has an area of 0.8925.
Now, we will use the binomial distribution to find the probability that exactly eight of them take more than 93.6 minutes, that is;
[tex]P(Y = y) = \binom{n}{r}\times p^{r} \times (1-p)^{n-r} ; y = 0,1,2,3,.........[/tex]
where, n = number of trials (samples) taken = 12 service calls
r = number of success = exactly 8
p = probability of success which in our question is probability that
it takes more than 93.6 minutes, i.e. p = 0.1075.
Let Y = Number of service calls which takes more than 93.6 minutes
So, Y ~ Binom(n = 12, p = 0.1075)
Now, the probability that exactly eight of them take more than 93.6 minutes is given by = P(Y = 8)
P(Y = 8) = [tex]\binom{12}{8}\times 0.1075^{8} \times (1-0.1075)^{12-8}[/tex]
= [tex]495 \times 0.1075^{8} \times 0.8925^{4}[/tex]
= 5.6015 [tex]\times 10^{-6}[/tex] .
Find the slope and y-intercept of this linear function:
2x + x = 4(y - 1)
Answer:
slope: 3/4y-intercept: 1Step-by-step explanation:
Solve for y to put the equation in slope-intercept form.
3x = 4y -4 . . . . . eliminate parentheses, collect terms
3x +4 = 4y . . . . . add 4
y = 3/4x +1 . . . . . divide by 4
The slope is the x-coefficient: 3/4.
The y-intercept is the constant: 1.
Which of the following sets would have a graph with an open circle on 5 and a ray pointing right on the number line?
The open circle means we do not include the endpoint, hence the use of a greater than symbol. If we were to include the endpoint, then we'd have greater than or equal to. We can rule out choice B due to this reasoning.
The ray pointing to the right indicates we are talking about x values larger than 5, so we can rule out choice A and conclude the answer is C.
Side note: The notation [tex]x \in \mathbb{R}[/tex] is saying "x is a real number"
Martin wants to use coordinate geometry to prove that the opposite sides of
a rectangle are congruent. He places parallelogram ABCD in the coordinate
plane so that A is (0,0), B is (a,0), Cis (a, b), and Dis (0, b).
What formula can he use to determine the distance from point D to point A?
Answer:
Option (B)
Step-by-step explanation:
Coordinates of the vertices of the rectangle were A(0, 0), B(a, 0), C(a, b) and D(0, b)
Formula to determine the distance between two points with the vertices (x, y) and (x', y') is,
d = [tex]\sqrt{(x-x')^2+(y-y')^2}[/tex]
For the length of AD,
AD = [tex]\sqrt{(0-0)^2+(b-0)^2}[/tex]
= [tex]\sqrt{b^2}[/tex]
= b
Therefore, Option (B) will be the answer.
Mrs. Fields needs more chocolate chips to make cookies. The store has bags that weigh 0.45 lbs., 0.434 lbs., and 0.4 lbs. Which bag should she purchase if she wants the most chocolate chips?
Answer:
bag weigh 0.45 lbs
Step-by-step explanation:
Evaluate x - 2y when x = 5 and y = 5.
Determine whether the ordered pair satisfies the equation.
x - 2y = -5; (5,5)
Yes, the ordered pair satisfies the equation.
No, the ordered pair does not satisfy the equation.
Answer:
For the first question we just plug in the values so we get 5 - 2 * 5 = -5.
Again, for the second one we'll plug in the values and see if it's a true statement. 5 - 2 * 5 = -5 and -5 = -5 so the answer is yes.
What is the value of X ?
Answer:
D
Step-by-step explanation:
2² + 6² = x²
4 + 36 = x²
40 = x²
x = 2√10
The sum of three consecutive odd numbers is 315 what are the numbers?
Answer:
Search Results
Featured snippet from the web
Which means that the first number is 104, the second number is 104 + 1 and the third number is 104 + 2. Therefore, three consecutive integers that add up to 315 are 104, 105, and 106.
Step-by-step explanation:
Write an
explicit formula for
ans
the nth
term of the sequence 20, -10,5, ....
Answer:an=20(-1/2)^n-1
Step-by-step explanation:
Damian reads 21 pages in 1 hour. How many pages can he read in 3 hours? StartFraction 21 pages Over 1 hour EndFraction = StartFraction question mark pages Over 3 hours EndFraction To go from 1 hour to 3 hours, you _______ . Damian can read _________ pages in 3 hours.
Answer: (Multiply by 3)
63 pages in 3 hours
Step-by-step explanation:
Answer:
To go from 1 hour to 3 hours, you
✔ multiply by 3
.
Damian can read
✔ 63
pages in 3 hours.
Step-by-step explanation:
Angle θ is in standard position. If (8, -15) is on the terminal ray of angle θ, find the values of the trigonometric functions.
sin(θ) =
cos(θ) =
tan(θ) =
csc(θ) =
sec(θ) =
✔ 17/8
cot(θ) =
✔ -8/15
i have only gotten the last two right and i need help with the others.
Answer:
cos =1/ sec
=8/17
tan =1/cot
= -15/8
sin = 15/17 or -15/17
cosec = 1/ sin
= 17/15 or -17/15
Answer:
Did the same assignment. lol can see how that went but here's the answers. hope it helps.
What is the answer to x>-8
Answer:
Sorry, I cant understand rewrite it again.
WILL GIVE BRAINLIST On a coordinate plane, 2 quadrilaterals are shown. The first figure has points A (negative 2, 1), B (negative 4, 1), C (negative 4, 5), and D (negative 2, 4). Figure 2 has points A prime (2, 1), B prime (4, 1), C prime (4, 5), and D prime (2, 4). What is the rule for the reflection? rx-axis(x, y) → (–x, y) ry-axis(x, y) → (–x, y) rx-axis(x, y) → (x, –y) ry-axis(x, y) → (x, –y)
Answer:
B) ry-axis(x, y) → (–x, y)
Step-by-step explanation:
Got it right on edge2020 you can trust me :D
Based on the measures shown, could the figure be a
parallelogram?
Answer:
its A
Step-by-step explanation:
ed 2020
Consider the following data representing the price of laptop computers (in dollars). 12041204, 12061206, 13451345, 13061306, 12071207, 10781078, 13571357, 12321232, 12281228, 13021302, 11891189, 11771177, 10831083, 10941094, 13261326, 10711071, 14271427, 13481348, 14201420, 12531253, 1270 Determine the frequency of the fifth class.
Answer:
Step-by-step explanation:
The given data is expressed as
1204, 1206, 1345, 1306, 1207, 1078, 1357, 1232, 1228, 1302, 1189, 1177, 1083, 1094, 1326, 1071, 1427, 1348, 1420, 1253, 1270
The number of items in the data, n is 21. The lowest value is 1071 while the highest value is 1427. The convenient starting point would be 1070.5 and the convenient ending point would be 1427.5
The number of class intervals is
√n = √21 = 4.5
Approximately 5
The width of each class interval is
(1427.5 - 1070.5)/5 = 72
The end of each class interval would be
1070.5 + 72 = 1142.5
1142.5 + 72 = 1214.5
1214.5 + 72 = 1286.5
1286.5 + 72 = 1358.5
1358.5 + 72 = 1430.5
The frequency for the fifth class, that is between 1358.5 to 1430.5 would be 2
Which statement about the two-way frequency table is true?
Answer:
Which statements?
Step-by-step explanation:
Can you write the statements please?
Na figura abaixo estão representadas cinco ruas do bairro onde moram João, Marcos, Pedro, Vitor e Samuel. A localização da casa de cada menino é identificada pela inicial de seu nome. Na esquina das ruas A e D fica a escola onde todos estudam. Sabe-se que as ruas A, B e C são paralelas e que todos os meninos vão a pé para a escola, sempre pelo caminho mais curto. Se Samuel caminha 100 m até a escola, Vitor caminha 260 m, João caminha 180 m e Marcos, 270 m, qual é a distância, em metros, que Pedro percorre de sua casa até a escola?
280m
300m
340m
460m
320m
Answer:
340 m
Step-by-step explanation:
Assume the figure looks like the one below.
We have three parallel lines cut by two transversals.
1. Lengths of segments
(a) Segment VS
If Vitor walks 260 m,
VS + SE = 260
VS + 100 = 260
VS = 260 - 100 = 160 m
(b) Segment MJ
If Marcos walks 270 m,
MJ + JE = 270
VS + 180 = 270
VS = 270 - 180 = 90 m
(c) Segment PV
The segments on the transversals are proportional.
[tex]\begin{array}{rcl}\dfrac{x}{90} & = & \dfrac{160}{180} \\\\x & = & 90 \times \left (\dfrac{160}{180}\right )\\\\& = &\textbf{80 m}\\\end{array}\\\textbf{PV = 80 m}[/tex]
2. Distance travelled by Pedro
Distance = PV + VS + SE = 80 m + 160 m + 100 m = 340 m
Pedro walks 340 m to school.
The speed of a passenger train is 6 mph faster than the speed of a freight train. The passenger train travels 260 miles in the same time it takes the freight train to travel 230 miles. Find the speed of each train.
Step-by-step explanation:
let speed of freight train be x
speed of passenger train = x+6
Passenger train distance = 280 miles
freight train 250 milesthe times taken for these distances is the same
280/(x+6)=250/x
280x=250(x+6)
280x=250x+1500
30x = 1500
x= 50 mph the speed of freight train.
x+6= 50+6 = 56mph = speed of passenger train.
Find the equation of the line through the points (-3,-3) and (2,-1) using point-slope form. Then rewrite the
equation in slope-intercept form.
Answer: See below
Step-by-step explanation:
The point-slope equation is y-y₁=m(x-x₁). Since we don't know our slope, we can use the formula [tex]m=\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex] to find the slope. All we have to do is use the coordinate we were given and plug it into the formula.
[tex]m=\frac{-1-(-3)}{2-(-3)} =\frac{2}{5}[/tex]
Now that we have the slope, we can fill out the point-slope equation.
y-(-3)=2/5(x-(-3))
y+6=2/5(x+3)
This is the point-slope form.
Now, we can distribute and solve to get slope-intercept form.
y+6=2/5x+6/5
y=2/5x-24/5
The market and Stock J have the following probability distributions:
Probability rM rJ
0.3 14% 22%
0.4 10 4
0.3 19 12
1. Calculate the expected rate of return for the market. Round your answer to two decimal places.%
2. Calculate the expected rate of return for Stock J. Round your answer to two decimal places.%
3. Calculate the standard deviation for the market. Round your answer to two decimal places.%
4. Calculate the standard deviation for Stock J. Round your answer to two decimal places.%
Answer:
1) [tex] E(M) = 14*0.3 + 10*0.4 + 19*0.3 = 13.9 \%[/tex]
2) [tex]E(J)= 22*0.3 + 4*0.4 + 12*0.3 = 11.8 \%[/tex]
3) [tex] E(M^2) = 14^2*0.3 + 10^2*0.4 + 19^2*0.3 = 207.1 [/tex]
And the variance would be given by:
[tex]Var (M)= E(M^2) -[E(M)]^2 = 207.1 -(13.9^2)= 13.89[/tex]
And the deviation would be:
[tex] Sd(M) = \sqrt{13.89}= 3.73[/tex]
4) [tex] E(J^2) = 22^2*0.3 + 4^2*0.4 + 12^2*0.3 =194.8 [/tex]
And the variance would be given by:
[tex]Var (J)= E(J^2) -[E(J)]^2 = 194.8 -(11.8^2)= 55.56[/tex]
And the deviation would be:
[tex] Sd(M) = \sqrt{55.56}= 7.45[/tex]
Step-by-step explanation:
For this case we have the following distributions given:
Probability M J
0.3 14% 22%
0.4 10% 4%
0.3 19% 12%
Part 1
The expected value is given by this formula:
[tex] E(X)=\sum_{i=1}^n X_i P(X_i)[/tex]
And replacing we got:
[tex] E(M) = 14*0.3 + 10*0.4 + 19*0.3 = 13.9 \%[/tex]
Part 2
[tex]E(J)= 22*0.3 + 4*0.4 + 12*0.3 = 11.8 \%[/tex]
Part 3
We can calculate the second moment first with the following formula:
[tex] E(M^2) = 14^2*0.3 + 10^2*0.4 + 19^2*0.3 = 207.1 [/tex]
And the variance would be given by:
[tex]Var (M)= E(M^2) -[E(M)]^2 = 207.1 -(13.9^2)= 13.89[/tex]
And the deviation would be:
[tex] Sd(M) = \sqrt{13.89}= 3.73[/tex]
Part 4
We can calculate the second moment first with the following formula:
[tex] E(J^2) = 22^2*0.3 + 4^2*0.4 + 12^2*0.3 =194.8 [/tex]
And the variance would be given by:
[tex]Var (J)= E(J^2) -[E(J)]^2 = 194.8 -(11.8^2)= 55.56[/tex]
And the deviation would be:
[tex] Sd(M) = \sqrt{55.56}= 7.45[/tex]