Suppose that Y has density function
f(y) = ky(1 − y) if 0 ≤ y ≤ 1 0, elsewhere
A) Find the value of k that makes f (y) a probability density function.
B) Find P(Y ≤ .4|Y ≤ .8).
C) Find the .95-quantile, i.e., find a point φ.95 such that P(Y ≤ φ.95) = .95.
I'm assuming
[tex]f(y)=\begin{cases}ky(1-y)&\text{for }0\le y\le1\\0&\text{otherwise}\end{cases}[/tex]
(a) f(x) is a valid probability density function if its integral over the support is 1:
[tex]\displaystyle\int_{-\infty}^\infty f(x)\,\mathrm dx=k\int_0^1 y(1-y)\,\mathrm dy=k\int_0^1(y-y^2)\,\mathrm dy=1[/tex]
Compute the integral:
[tex]\displaystyle\int_0^1(y-y^2)\,\mathrm dy=\left(\frac{y^2}2-\frac{y^3}3\right)\bigg|_0^1=\frac12-\frac13=\frac16[/tex]
So we have
k / 6 = 1 → k = 6
(b) By definition of conditional probability,
P(Y ≤ 0.4 | Y ≤ 0.8) = P(Y ≤ 0.4 and Y ≤ 0.8) / P(Y ≤ 0.8)
P(Y ≤ 0.4 | Y ≤ 0.8) = P(Y ≤ 0.4) / P(Y ≤ 0.8)
It makes sense to derive the cumulative distribution function (CDF) for the rest of the problem, since F(y) = P(Y ≤ y).
We have
[tex]\displaystyle F(y)=\int_{-\infty}^y f(t)\,\mathrm dt=\int_0^y6t(1-t)\,\mathrm dt=\begin{cases}0&\text{for }y<0\\3y^2-2y^3&\text{for }0\le y<1\\1&\text{for }y\ge1\end{cases}[/tex]
Then
P(Y ≤ 0.4) = F (0.4) = 0.352
P(Y ≤ 0.8) = F (0.8) = 0.896
and so
P(Y ≤ 0.4 | Y ≤ 0.8) = 0.352 / 0.896 ≈ 0.393
(c) The 0.95 quantile is the value φ such that
P(Y ≤ φ) = 0.95
In terms of the integral definition of the CDF, we have solve for φ such that
[tex]\displaystyle\int_{-\infty}^\varphi f(y)\,\mathrm dy=0.95[/tex]
We have
[tex]\displaystyle\int_{-\infty}^\varphi f(y)\,\mathrm dy=\int_0^\varphi 6y(1-y)\,\mathrm dy=(3y^2-2y^3)\bigg|_0^\varphi = 0.95[/tex]
which reduces to the cubic
3φ² - 2φ³ = 0.95
Use a calculator to solve this and find that φ ≈ 0.865.
Using probability concepts, it is found that
a) The value is k = 6.
b) P(Y ≤ .4|Y ≤ .8) = 0.554.
c) The 95th percentile is x = 0.86465.
The density function is:
[tex]f(y) = ky(1 - y)[/tex]
Item a:
The condition that makes it a probability density function is:
[tex]\int_0^1 f(y) dy = 1[/tex]
Thus:
[tex]\int_0^1 f(y) dy = \int_0^1 ky - ky^2 dy[/tex]
[tex]\int_0^1 f(y) dy = k(\frac{y^2}{2} - \frac{y^3}{3})|_{y = 0}^{y = 1}[/tex]
[tex]\int_0^1 f(y) dy = k(\frac{1}{2} - \frac{1}{3})[/tex]
Then
[tex]k(\frac{1}{2} - \frac{1}{3}) = 1[/tex]
[tex]k(\frac{3-2}{6}) = 1[/tex]
[tex]k = 6[/tex]
The value is k = 6.
Item b:
This probability is:
[tex]\int_0.4^0.8 f(y) dy = 6(\frac{y^2}{2} - \frac{y^3}{3})|_{y = 0.4}^{y = 0.8}[/tex]
Then
[tex]p = 6\left(\frac{0.8^2}{2} - \frac{0.8^3}{3} - \frac{0.4^2}{2} + \frac{0.4^3}{3}\right)[/tex]
[tex]p = 0.554[/tex]
Thus, P(Y ≤ .4|Y ≤ .8) = 0.554.
Item c:
This is x for which:
[tex]\int_0^x f(y) dy = 0.95[/tex]
Thus:
[tex]6(\frac{x^2}{2} - \frac{x^3}{3}) = 0.95[/tex]
[tex]-2x^3 + 3x^2 - 0.95 = 0[/tex]
Solving a cubic equation with the help of a calculator, and considering [tex]0 \leq x \leq 1[/tex], this is x = 0.86465.
A similar problem is given at https://brainly.com/question/22223588
The cost of an item is $0.30 per ounce. If total cost of the item is $3.60, how many ounces are in the item?
Answer:
Example 1: - If the item's label displays the weight as 3 lb 2 oz, type the shop name and item's brand, enter 3 in the pounds field, leave the 00 (decimal) value unchanged, enter 2 in the ounces field, leave the 00 (decimal) value unchanged, fill out the Price field and Calculate to get the price per ounce
Answer:
12 ounces
Step-by-step explanation:
3.60 = .3x
divide by .3 on both sides
12 = x
Explain how multiplying fractions and dividing fractions are alike and how they are different.
Answer:
Multiplying and dividing fractions are essentially the same process which you multiply the numbers straight across and no need for common denominators. Except in division of fractions, the second fraction is flipped so that the denominator is on the top and the numerator is on the bottom (reciprocal).
Step-by-step explanation:
Example:
[tex]\frac{3}{4} * \frac{1}{5} = \frac{3}{20}[/tex]
[tex]\frac{3}{4}[/tex] ÷ [tex]\frac{1}{5} = \frac{3}{4} * \frac{5}{1} = \frac{15}{4}[/tex]
Salvador is 15 years older than Elizabeth. In 6 years, the sum of their ages will be 87. How old are they now?
please include and explantation
Answer:
????
Step-by-step explanation:
The GCF of 15 and 27
9x+6+4x-2x+1-15
What is the answer?
Answer: 3x - 8
Hope it helps!
Answer:
9 + 6 + 4 − 2 + 1 − 1 5
9x+{\color{#c92786}{6}}+4x-2x+{\color{#c92786}{1}}{\color{#c92786}{-15}}
9x+6+4x−2x+1−15
9 − 8 + 4 − 2
Step-by-step explanation:
x + 3y = 13
- 3x + 2y = 27 steps on how to solve by substitution
here x+3y=13
x=13-3y.....1st equation
-3x+2y=27......2nd euation
now putting the value of x from equation 1st in 2nd we will get
-3(13-3y)+2y=27
-49+9y+2y=27
11y=27+49
y=76÷11
y=6.9
now again putting the value of y in equation 1st we get
x=13-3×6.9
x=13-20.7
x=7.7
Multiply two and four-fifths negative five and two-thirds
Evaluate the function for x = 2,3,4
F(x) =2x-7-3
Answer:
below in bold
Step-by-step explanation:
f(x) = 2x - 7 - 3
~Combine like terms
f(x) = 2x - 10
When x = 2...
f(x) = 2(2) - 10
f(x) = 4 - 10
f(x) = -6
When x = 3...
f(x) = 2(3) - 10
f(x) = 6 - 10
f(x) = -4
When x = 4...
f(x) = 2(4) - 10
f(x) = 8 - 10
f(x) = -2
Best of Luck!
Peter collected 171 marbles but lost 3/4 of them on his way home through of hole in his bag when he arrived at home now many marbles did Peter have left?
The number of marbles Peter had when he arrived home was 43 marbles
What is Percentage?
A percentage is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, %
Given data ,
The number of marbles Peter had on his way home = 171
The amount of marbles he lost on his way home = ( 3/4 ) th
Now , the amount of marbles Peter have left = 1 - amount of marbles he lost on his way home
The amount of marbles Peter have left = 1 - 3/4
= ( 1 / 4) th
So , The number of marbles Peter had left when he arrived home is =
Amount of marbles Peter have left x Number of marbles Peter had
The number of marbles Peter had left when he arrived home is = (1/4) x 171
= 171 / 4
= 42.75
≈ 43 marbles
Hence , the number of marbles Peter had left when he reached home is 43
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If 6 x 7 = 26 +0, find the number that belongs in the box.
211
Which angles are adjacent angles to 3? Select all that apply
Two Answers: Angle 1, Angle 4
Adjacent angles share a common segment, line, or ray. Think of two adjacent rooms sharing a common wall.
4. The value of a copy machine is $8500 when it is purchased. After two years its value is $7475. What is its value after 8 years?
Answer:
3375 is the answer.
Step-by-step explanation: 8500- 1025=7475
so 1025 is every to years so we need to subtract 7475-1025-1025-1025-1025 so each 1025 is 2 yrs.
I hope this works :)
how do you find the distance between two negative fractions
Answer:
Use the number line and split the whole numbers into fractions
Step-by-step explanation:
Example: If a number line goes from -10 all the way to +10, and you are trying to find the distance between -2 1/4 and -7 3/4. You would split the number line into fourths and then locate -7 3/4. You would then count up to -2 1/4 to get 4 3/4.
Hopefully this makes sense!
Which reason justifies statement 2?
A) Vertical angles are congruent
B) Corresponding angles are congruent
C) Alternate interior angles are congruent
D) Alternate exterior angles are congruent
Answer:
Step-by-step explanation:
Is b) corresponding angles are congruent.
The reason that justifies statement two: "Angle Y ≅ Angle 4", is option C "Alternate interior angles are congruent".
What are congruent angles?Angles that are of the same measurement are called congruent.
Suppose that two angles ∠A and ∠B are of the same measure, then
[tex]m\angle A = m\angle B[/tex] is the notation to say that they are of the same measurement, where the small m shows that it's the measurement's the angles they're preceding.
We can see that angle Y and angle 4 are two alternate angles within the two parallel lines cut across by the transversal, therefore, they are called alternate interior angles.
Since Alternate interior angles are always congruent to each other.
Thwithefore, the reason that justifies statement two: "Angle Y ≅ Angle 4", is "Alternate interior angles are congruent".
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Which phrase describes how to divide a complex number z by r(cos θ + i sin θ)?
Scale by a factor of StartFraction 1 Over r EndFraction and rotate clockwise by θ.
Scale by a factor of r and rotate clockwise by θ.
Scale by a factor of StartFraction 1 Over r EndFraction and rotate counterclockwise by θ.
Scale by a factor of r and rotate counterclockwise by θ.
Answer:
its a
Step-by-step explanation:
The phrase is Scale by a factor of 1 /r and rotate clockwise by θ.
What is complex number?Complex numbers are numbers that consist of two parts — a real number and an imaginary number.
Given:
z=r(cos θ + i sin θ)
So, to divide a complex number the best phrase to describe is Scale by a factor of 1 /r and rotate clockwise by θ.
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The equation F= 9/5C +32 relates temperature measured in degrees Celsius. C, to degrees Fahrenheit, F. Determine whether there is a proportional relationship between C and F.
Given:
The equation is
[tex]F=\dfrac{9}{5}C+32[/tex]
To find:
Whether there is a proportional relationship between C and F.
Solution:
If there is a proportional relationship between C and F, then the line of given equation passes through (0,0) and the equation must be true for (0,0).
Put F=0 and C=0 in the given equation.
[tex]0=\dfrac{9}{5}(0)+32[/tex]
[tex]0=0+32[/tex]
[tex]0=32[/tex]
This statement is not true because [tex]0\neq 32[/tex].
It means the line of given equation does not passes through (0,0). So, it s not a proportional relationship.
Hence, there is not a proportional relationship between C and F.
Answer:
korrect
Step-by-step explanation:
it looks right
Which of the following is a biconditional statement?
Question 17 options:
A)
If x ≠ 5 then x2 ≠ 25
B)
If x2 = 25, then x = 5 or x = –5
C)
x = 5 if x2 = 25
D)
x = 5 if and only if x + 5 = 10
It is D
I just took the test and got it right
The biconditional statement is x = 5 if and only if x + 5 = 10.
Option D is the correct answer.
What is an expression?An expression is a way of writing a statement with more than two variables or numbers with operations such as addition, subtraction, multiplication, and division.
Example: 2 + 3x + 4y = 7 is an expression.
We have,
Biconditional statement.
This means,
The statement and its converse are both true.
Now,
x = 5 if and only if x + 5 = 10
This shows that both the statement and its converse are true.
Thus,
x = 5 if and only if x + 5 = 10 is a biconditional statement.
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Karen spent 39 minutes knitting 3 hats. In all, how many hats could Karen knit in 117 minutes
Bella wants to create a tea-mix. She can buy Asian Treasure tea for $7.50 per ounce and Paradise tea for $5.00 per ounce. If she wants to make 60 ounces of tea-mix at a cost of $6.00 per ounce, how many ounces of Asian Treasure tea and how many ounces of Paradise tea should she buy?
9514 1404 393
Answer:
24 oz Asian Treasure36 oz ParadiseStep-by-step explanation:
The proportion of Asian Treasure is the difference in price of the mix and Paradise tea, divided by the difference in price of Asian Treasure and Paradise tea. So the amount of Asian Treasure is ...
(6.00 -5.00)/(7.50 -5.00)(60 ounces) = 24 ounces . . . Asian Treasure tea
The remaining 60-24 = 36 ounces will be Paradise tea.
__
Using an equation
You can get the same result if you define a variable (a) to the amount in ounces of the higher-priced contributor. Then the lower-priced contributor will be in the amount (60-a) ounces. The total cost of the mix is ...
7.50a +5.00(60 -a) = 60(6.00)
(7.50 -5.00)a +60(5.00) = 60(6.00) . . . rearrange the left side
(7.50 -5.00)a = 60(6.00 - 5.00) . . . . . . subtract 60(5.00)
a = 60(6.00 -5.00)/(7.50 -5.00) . . . . . . divide by the coefficient of 'a'
Note that this last expression is identical to the one we used above to find the quantity of Asian Treasure tea.
You can tell if the value of a function for a certain interval is positive just by 2 points looking at its graph. If the value is positive that part of the graph will:
a: be to the right of the y-axis
b: be above the x-axis
c: intersect the x-axis
d: be below the x-axis
PLEASE HELP QUICKLY!!!!! PLZZZZZZ!!!!!!!
Students will be going to the zoo in a field trip entrance fee is $6.00 and you will be able to purchase drinks or food items for $2.00 each write an equation indicating the total cost of going to the zoo
Answer:
c = 6+2x
Step-by-step explanation:
c = total cost, 6 = entrance fee, 2x = 2 dollars per food/drink item
Evaluate the expression 8-3×2+5
Answer:
7
Step-by-step explanation:
First do 3x2 to get 6, and then do 8-6, which is 2, and add that to 5 to get 7
What are all of the possible classifications for a 3 × 3 system? Check all of the boxes that apply.
consistent and dependent
consistent and independent
inconsistent and dependent
inconsistent and independent
Answer:
consistent and dependent
consistent and independent
inconsistent and independent
Step-by-step explanation:
Answer:
1
2
4
Step-by-step explanation:
has nice day
5. Cherries are on sale for $16 for 4 pounds. Jordyn pays $28.00 for
cherries to make a cobbler. How many pounds of cherries does she buy? *
Answer:
7 pounds
Step-by-step explanation:
1 pound is $4 28/4 is 7
I need help with 10 please!!!!!!!
From the graph, [tex]y=mx+b[/tex] and m < 0 (The slope right here is less than 0.)
That means cut ( b ) and ( d ) choice, they both are wrong.
Now look at ( a ) and ( c ).
For ( a ) It's just f(x) = -2x but the graph that's shown here intercepts y-axis at (0,2). f(x) = -2x is just slope and intercepts y-axis at (0,0)
So the answer is ( c )
Write a fraction that is equal to 5
Answer:
5/1
Step-by-step explanation:
How many solutions does the absolute value equation have?
I x - 3 I + 2 = -2
9514 1404 393
Answer:
the correct answer is marked
Step-by-step explanation:
When the graph of the left side of the equation does not intersect the graph of the right side of the equation, there are no solutions.
__
Additional comment
Even if you extend the domain to complex numbers, there are no solutions. The f(x) = |x| function always returns a positive real value, even for complex numbers.
Find the slope using the formula.
(-2,-9) and (-6,-6)
Answer:(3,-4) you just have to follow the equation.
Slope = change in y over change in x.
Slope = (-6 - -9) / (-6 - -2)
Slope = (-6 + 9) / (-6 + 2)
Slope = 3/-4
Slope = -3/4