Given that X and Y are independent variables.
Let Mx (t) = E [e^tX]My (t) = E [e^tY]Mx+y (t) = E [e^t (X+Y)]Mx+y (t) = E [e^tX * e^tY] (Since X and Y are independent)Mx+y (t) = E [e^tX] * E [e^tY] (As X and Y are independent, E [X+Y] = E [X] + E [Y])Mx+y (t) = Mx (t) * My (t) ………………
(1)Now, let’s prove that Var (X+Y) = Var (X) + Var (Y)Var (X+Y) = E [(X+Y)^2] – E [X+Y]^2Var (X+Y) = E [X^2 + Y^2 + 2XY] – [E (X) + E (Y)]^2 (Expanding the square of X+Y)Var (X+Y) = E [X^2] + E [Y^2] + 2 E [XY] – [E (X)^2 + E (Y)^2 + 2E (X)E (Y)]Var (X+Y) = (E [X^2] – E [X]^2) + (E [Y^2] – E [Y]^2) + 2 (E [XY] – E [X] E [Y])Var (X+Y) = Var (X) + Var (Y) + 2 Cov (X,Y) ………………
(2)Now, let’s prove that mx-y(t) = mx (t)my (-t)Mx-y (t) = E [e^t (X-Y)] = E [e^tX / e^tY] = E [e^(t (X-Y))] / E [e^tY] ……………… (3) (By the property of division)Multiplying and dividing the numerator of equation (3) by e^tY, we get, Mx-y (t) = E [e^tX + (-Y)] * e^(-tY) / E [e^tY]Mx-y (t) = Mx (t) * My (-t) ………………
(4)Now, let’s prove that Var (X-Y) = Var (X) + Var (Y) – 2 Cov (X,Y)Var (X-Y) = E [(X-Y)^2] – [E (X-Y)]^2Var (X-Y) = E [(X^2 + Y^2 – 2XY)] – [(E (X) – E (Y))]^2Expanding the square in the second term, we get, Var (X-Y) = E [X^2 + Y^2 – 2XY] – E [X]^2 – E [Y]^2 + 2E [X] E [Y]Var (X-Y) = (E [X^2] – E [X]^2) + (E [Y^2] – E [Y]^2) – 2 (E [XY] – E [X] E [Y])Var (X-Y) = Var (X) + Var (Y) – 2 Cov (X,Y) ………………
(5) From equations (2) and (5), we can write, Var (X+Y) + Var (X-Y) = 2 (Var (X) + Var (Y)) Therefore, Var (X+Y) = Var (X) + Var (Y)
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(11m-7m)-(2m+6m) the sum or differce
Answer:
-4m
Step-by-step explanation:
=11m-7m-(2m+6m)
=11m-7m-8m
=-4m
plz mark me as brainliest
Answer:
-4m
Step-by-step explanation:
Hey!
==================================================================
First, We should remove the Parentheses.
To remove them, we distribute the negative over (2m + 6m).
⇒ 11m - 7m - (2m + 6m)
⇒ 11m - 7m - 2m - 6m
Work the Problem from Left to Right.
⇒ 4m - 2m - 6m
⇒ 2m - 6m
⇒ -4m
==================================================================
Hope I Helped, Feel free to ask any questions to clarify :)
Have a great day!
More Love, More Peace, Less Hate.
-Aadi x
For a, b, c, d € Z, prove that a - c|ab + cd if and only if a - cl ad + bc. 2. (a) What are the possible remainders when 12 + 16 + 20 is divided by 11? (b) Prove for every n € Z that 121 + n2 +
The statement "a - c|ab + cd if and only if a - cl ad + bc" is false. It does not hold for all values of a, b, c, and d in the set of integers.
The given statement is not true in general. To prove its falseness, we can provide a counterexample. Consider a = 2, b = 3, c = 1, and d = 4. Using these values, we have a - c = 2 - 1 = 1.
However, ab + cd = (2)(3) + (1)(4) = 10, which is not divisible by 1. On the other hand, a - cl ad + bc = 2 - (1)(2)(4) + (1)(3) = -2 + 3 = 1. Here, a - cl ad + bc equals a - c, but ab + cd does not satisfy the divisibility condition. Hence, the given statement is false.
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Find the value of x for which / || m
Answer:
x = 26
Step-by-step explanation:
Let c represent how much it costs for one person to go to a baseball game. How can we represent the total cost for 6 people to go to the game? A. 6c B. c – 6 C. D. c + 6
Answer:
6c for the total
Yes, I need help, give answer as IMPROPER fraction.
Answer:
[tex]w = \frac{93}{40} [/tex]
Help on this please asap
Answer:
87.75
Step-by-step explanation:
You are correct
The Histogram displays information about speeds of motorcycles in miles per hour. What is the number of motorcycles traveling less than 40 miles per hour? A. 30 B. 40 C. 60 D. 20
Answer:
D. 50
Step-by-step explanation:
50-54 is 30
55-59 is 20
Let f be a given function. a A graphical interpretation of the 2-point backward difference formula for approximating f'(x0) is the slope of the line joining the points of abscissas xo - h and xo with h > 0.
The 2-point backward difference formula for approximating the derivative of a function at a point x0 is graphically represented by the slope of the line connecting the points (x0 - h, f(x0 - h)) and (x0, f(x0)), where h is a positive value.
The 2-point backward difference formula is a numerical method used to approximate the derivative of a function at a specific point. To understand its graphical interpretation, consider a function f and a point x0 on its graph. The formula involves calculating the slope of a line that connects two points on the graph. The first point is (x0 - h, f(x0 - h)), which corresponds to a slightly shifted x-value from x0, denoted as x0 - h, and its corresponding y-value is f(x0 - h). The second point is (x0, f(x0)), representing the original point on the graph. The value of h is chosen to be positive, indicating that the first point is to the left of the second point. By calculating the slope of the line connecting these two points using the familiar slope formula, rise over run, we obtain an approximation of the derivative of the function at x0 using the 2-point backward difference formula.
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The radius of a circle is 4 feet. What is the area?
r=4ft
Give the exact answer in simplest form.
_____ square feet
PLEASE HELP I NEED HELP
Plzzzzz i need help!!!!!
Step-by-step explanation:
here is the anewer then change in fractionFind the following cardinalities: a. |A| when A= {2,3,4,5,..., 38). } = b. A when A= {re Z:-1
(a) The cardinality of A is 37.
The set A is defined as {2, 3, 4, 5, ..., 38}, which is a set of consecutive integers. To find the cardinality of A, we count the number of elements in the set. We can do this by subtracting the smallest element from the largest element and then adding 1:
|A| = 38 - 2 + 1 = 37
Therefore, the cardinality of A is 37.
(b) The cardinality of A is 16.
The set A is defined as the set of all complex numbers of the form a + bi, where a and b are integers such that -1 ≤ a ≤ 2 and -2 ≤ b ≤ 1. To find the cardinality of A, we count the number of elements in the set.
The set of possible values for a is {-1, 0, 1, 2}, and the set of possible values for b is {-2, -1, 0, 1}. Therefore, the set A has 4 × 4 = 16 elements.
Alternatively, we can write out all the elements in the set:
A = {-1 - 2i, -1 - i, -1, -1 + i, 0 - 2i, 0 - i, 0, 0 + i, 1 - 2i, 1 - i, 1, 1 + i, 2 - 2i, 2 - i, 2, 2 + i}
Therefore, the cardinality of A is 16.
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The Baltimore Mean Green is a local tennis team which currently has twenty-three members. If only six people can participate at the same time and positions are not considered, how many different groups of members can be selected?
Therefore, there are 23,725 different groups of six members that can be selected from the twenty-three members of the Baltimore Mean Green tennis team.
What is the probability of rolling a sum of 7 with two fair six-sided dice?In this scenario, we are interested in determining the number of different groups of members that can be selected from a total of twenty-three members to form a team of six.
Since the order of selection and specific positions within the team are not considered, we are dealing with combinations rather than permutations.
To calculate the number of combinations, we can use the concept of binomial coefficients. The formula for calculating binomial coefficients is:
C(n, k) = n! / (k!(n-k)!)Where n represents the total number of items or members (in this case, 23), and k represents the number of items or members to be selected (in this case, 6). The exclamation mark denotes the factorial operation.
Applying the formula, we can calculate the number of combinations as follows:
C(23, 6) = 23! / (6!(23-6)!)= 23! / (6!17!)After performing the calculations, we find that the number of different groups of members that can be selected is:
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Assume that a sample is used to estimate a population mean . Find the 99% confidence intervat for a Sample of size 68 with a mean of 65.9 and a standard deviation of 16.5. Enter your answer as an open- interval (low, high)
The 99% confidence interval for the population mean based on the given sample is (61.86, 69.94). This means that we are 99% confident that the true population mean falls within this interval.
To find the 99% confidence interval for a sample with a sample size of 68, a sample mean of 65.9, and a standard deviation of 16.5, we can use the formula for calculating the confidence interval for a population mean when the population standard deviation is known.
The formula is given by:
Confidence Interval = (sample mean) ± (critical value) * (standard deviation / sqrt(sample size))
First, we need to find the critical value corresponding to a 99% confidence level. Since the sample size is large (n = 68), we can use the Z-table or a Z-table calculator to find the critical value. For a 99% confidence level, the critical value is approximately 2.576.
Next, we can substitute the given values into the formula to calculate the confidence interval:
Confidence Interval = 65.9 ± 2.576 * (16.5 / sqrt(68))
Using a calculator or mathematical software, we can calculate the standard error of the mean:
Standard Error = standard deviation / sqrt(sample size) = 16.5 / sqrt(68) ≈ 1.997
Substituting the standard error into the formula, we have:
Confidence Interval = 65.9 ± 2.576 * 1.997
Calculating the values inside the interval, we get:
Confidence Interval = (65.9 - 2.576 * 1.997, 65.9 + 2.576 * 1.997)
Simplifying further, we have:
Confidence Interval = (61.86, 69.94)
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An object is dropped from a bridge and allowed to freefall to the ground. The height of the object over time can be modeled using h(t) = 144 – 16t2.
Answer:
3 seconds
Step-by-step explanation:
Complete question:
An object is dropped from a bridge and allowed to freefall to the ground. The height of the object over time can be modeled using h(t)=144-16t2. How many seconds will it take the object to reach the ground? 2 seconds 3 seconds 9 seconds 16 seconds
Given the height of an object modelled by the expression;
h(t)=144-16t²
The object will reach the ground when h(t) = 0
Substitute into the formula
0 = 144 - 16t²
-144 = -16t²
144 = 16t²
Swap
16t² = 144
t² = 144/16
t² = 9
Square root both sides
√t² = ±√9
t = ±3secs
Since the time cannot be negative, hence the object will reach the ground 3 seconds after
The object below is made of solid plastic. It is a cylinder with an indentation at the top in the shape of a cone. What is the volume of the object (in cubic inches)? *
Answer:
97.6 cm³
Step-by-step explanation:
Volume of plastic object :
Volume of cylinder - volume of cone
From. The diagram. :
Radius, r = diameter /2 = 4/2
Volume of cylinder = pi*r²h
V = 22/7 * 2² * 8 = 100.53096 cm³
Volume of cone = 1/3*pi*r²h
V = 1/3 * 22/7 * 2² * 8
V = 2.9321531 cm³
(100.53096 - 2.9321531) cm³
= 97.598 cm³
= 97.6 cm³
What are the angles in degreees
Answer: A is 70 B is 45 and C is 50
Step-by-step explanation:
A chef at a restaurant uses pounds of butter each day. About how many grams of butter does the chef use each day? Use the conversion factors and .
Complete question :
A chef at a restaurant uses 12 pounds of butter each day. About how many grams of butter does the chef use each day? use the conversion factors 16 oz/1 lb and 28.35 grams/1oz
Answer:
5,424 grams
Step-by-step explanation:
To convert using the conversion factor :
Number of pounds of butter * (16 oz/1) * (28.35) /1
Hence,
12 * 16oz/ 1 * 28.35/1
(12 * 16 * 28)
= 5,424 grams
Please i need help. Thank you!
Manual Transmission Automobiles in 1980 more than 35% of cars purchased had a manual transmission (I.e. stick shift). By 2007 the proportion had decreased to 7.7%. A random sample of college students who owned cars revealed the following: out of 121 cars, 22 had stick shifts. Estimate the proportion of college students who drive sticks with 90% confidence. Use a graphing calculator and round the answers to at least three decimal places.
The estimated proportion of college students who drive stick shift cars is calculated with 90% confidence using sample data.
To estimate the proportion of college students who drive stick shift cars, we can use the sample data of 121 cars, out of which 22 have stick shifts. We will construct a confidence interval to estimate the true proportion. Using a graphing calculator, we can perform a proportion confidence interval calculation.
The calculator will take into account the sample size, the number of successes (cars with stick shifts), and the desired confidence level (90% in this case).
The resulting confidence interval will provide an estimate of the proportion of college students who drive stick shift cars. The answer should be rounded to at least three decimal places for accuracy.
This interval will represent a range within which we can be 90% confident that the true proportion of college students who drive stick shift cars lies.
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Yeah help guys today was way to stressful to do this shi right now
Answer:
15.3125
Step-by-step explanation:
i gotchu
A carnival game has 160 rubber ducks floating in a pool. The person playing the game takes out one duck and looks at it.
I
f there’s a red mark on the bottom of the duck, the person wins a small prize.
If there’s a blue mark on the bottom of the duck, the person wins a large prize.
Many ducks do not have a mark.
After 50 people have played the game, only 3 of them have won a small prize, and none of them have won a large prize.
Estimate the number of the 160 ducks that you think have red marks on the bottom
Answer:
I think there are about 16-20 ducks with red marks on them.
Answer:
Around 10 ducks have a red mark
() = 0.50, () = 0.70, ( ∪ ) = 0.85 Are the events, and , independent in this situation? You must provide reasoning for your answer.
Answer:
Independent events
Step-by-step explanation:
Given
[tex]P(A) = 0.50[/tex]
[tex]P(B)= 0.70[/tex]
[tex]P(A\ u\ B) = 0.85[/tex]
Required
Determine the relationship between the events
To do this, we simply calculate P(A n B) using:
[tex]P(A\ n\ B) = P(A) * P(B)[/tex]
and
[tex]P(A\ n\ B) = P(A) + P(B) - P(A\ u\ B)[/tex]
So, we have:
[tex]P(A\ n\ B) = P(A) * P(B)[/tex]
[tex]P(A\ n\ B) = 0.50 * 0.70[/tex]
[tex]P(A\ n\ B) = 0.35[/tex]
and
[tex]P(A\ n\ B) = P(A) + P(B) - P(A\ u\ B)[/tex]
[tex]P(A\ n\ B) = 0.50 + 0.70 - 0.85[/tex]
[tex]P(A\ n\ B) = 0.35[/tex]
Since: [tex]P(A\ n\ B) = P(A) * P(B)[/tex] [tex]= 0.35[/tex]
Then: the events are independent
What is the measure of the angle supplementary to a 47.5 degree angle?
137.5
52.5
42.5
152.5
Answer:
132.5 degrees. Check to see if there is missing information in the question or any mistakes.
Step-by-step explanation:
Supplementary angles = 180 degrees
180 - 47.5 = 132.5
Evaluate the line integrals.
a. C is the line segment from (-1.0.2) to (1,-3,8) ∫_{c} yz ds
The line integral is -165/7.
The given line integral is ∫ ds, where is the line segment from (−1,0,2) to (1,−3,8).
The line integral is given by the following formula:
∫ (,,) ds = ∫_^ ((),(),()) ||'()|| d
Here,() = 2 − 1, () = −3, () = 6 + 2and a = 0 and b = 1.
We know that ds = ||'()|| d.
Let us find '() first.'() = 〈2,−3,6〉,
therefore, ||'()|| = √(2² + (−3)² + 6²) = 7
So, ds = 7dt.
We need to find the value of (,,) at each of the parameterizations, so let us find those next.
(,,) = = (−3)(6 + 2) = −18² − 6
Now we can compute the integral:
∫ ds=∫0^1(−18² − 6)7=−162/7 - 3/7= −(165/7)
Therefore, the value of the line integral is -165/7.
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i need help with math?
Answer:
B.
3^4 = 81
3^2 = 9
81/9 = 9
Step-by-step explanation:
Answer: B. 9
Step-by-step explanation:
3^4-2=3²
3²=9
help needed for this question please
Answer:
11.72sq.m
Step-by-step explanation:
Area of the shaded region = Area o triangle - Area of the semicircle
Area of triangle = 1/2 * base * height
Area of triangle = 1/2 * 6 * 6
Area of triangle = 3 * 6
Area of triangle = 18sq. m
Area of semicircle = πr²/2
r is the radius = 2m
Area of semicircle = π(2)²/2
Area of semicircle = 2(3.14)
Area of semicircle = 6.28sq. m
Area of the shaded region = 18 - 6.28
Area of the shaded region = 11.72sq.m
*
2) Does the following table show a function?
Answer:
no it does not show a fucntion
How many gallons of water are used to fill 2 fish tanks
Answer:
It depends on the size of the fish tank, so this question cannot be properly answered.
Answer:It depends I can give a ratio
Step-by-step explanation:
If one tank needs 45 gallons of water and another needs 30 you will need 75 gallons of water. If your using pints or quarts you can find converter calculators
How do I find the height of a cylinder from only knowing the volume and radius?
r=6 V=565.2 for the specifics of the question I have
Answer:
4.997
Step-by-step explanation: