======================================================
Explanation:
PDF = probability density function
The given joint PDF is
[tex]f(x,y) = \begin{cases}ax \ \ \ \text{ if } 1 \le x \le y \le 2\\0 \ \ \ \ \ \text{ otherwise}\end{cases}[/tex]
Let's focus on the [tex]1 \le x \le y \le 2[/tex]. Specifically the x term for now. Erasing out the y term, we have the inequality [tex]1 \le x \le 2[/tex] which says x is between 1 and 2, inclusive. We have almost the same story for y, but there's another condition attached to it: y must also be equal to or larger than x.
So let's say x = 1.5. This would mean [tex]1.5 \le y \le 2[/tex]. As another example, x = 1.7 leads to [tex]1.7 \le y \le 2[/tex]. In general, we would say [tex]x \le y \le 2[/tex] where x is between 1 and 2.
As x gets bigger, the range of possible y values gets smaller. If x = 2, then y has no choice but to be 2 as well.
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Based on that, we'll have a double integral that looks like this:
[tex]\displaystyle V = \int_{1}^{2}\int_{x}^{2}f(x,y)dydx\\\\[/tex]
The outer integral handles the x terms that range from 1 to 2, describing [tex]1 \le x \le 2[/tex]. Note the dx on the outside. The order of the dy and dx matters.
On the inside, we have the integral for dy ranging from x to 2 to describe the interval [tex]x \le y \le 2[/tex]
To have f(x,y) be a PDF, the volume under the f(x,y) surface must be 1, where the volume is based on the bounds set up. So we must have V = 1. We'll use this later.
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Let's simplify the double integral.
We'll start by computing the inner integral with respect to y.
[tex]\displaystyle V = \int_{1}^{2}\int_{x}^{2}f(x,y)dydx\\\\\displaystyle V = \int_{1}^{2}\int_{x}^{2}\left(ax\right)dydx\\\\\displaystyle V = \int_{1}^{2}\left(axy\Bigg|_{x}^{2}\right)dx\\\\\displaystyle V = \int_{1}^{2}\left(ax(2) - ax(x)\right)dx\\\\\displaystyle V = \int_{1}^{2}\left(2ax - ax^2\right)dx\\\\[/tex]
Then we'll finish it off by integrating with respect to x.
[tex]\displaystyle V = \int_{1}^{2}\left(2ax - ax^2\right)dx\\\\\displaystyle V = \left(ax^2 - \frac{1}{3}ax^3\right)\Bigg|_{1}^{2}\\\\\displaystyle V = \left(a(2)^2 - \frac{1}{3}a(2)^3\right) - \left(a(1)^2 - \frac{1}{3}a(1)^3\right)\\\\\displaystyle V = \left(4a - \frac{8}{3}a\right)-\left(a - \frac{1}{3}a\right)\\\\[/tex]
[tex]\displaystyle V = 4a - \frac{8}{3}a-a + \frac{1}{3}a\\\\\displaystyle V = 3a - \frac{8}{3}a + \frac{1}{3}a\\\\\displaystyle V = \frac{9}{3}a - \frac{8}{3}a + \frac{1}{3}a\\\\\displaystyle V = \frac{9-8+1}{3}a\\\\\displaystyle V = \frac{2}{3}a\\\\[/tex]
Side note: We don't have to worry about the "plus C" integration constant when working with definite integrals.
Recall that V = 1. So,
[tex]\displaystyle V = \frac{2}{3}a\\\\\displaystyle \frac{2}{3}a = 1\\\\\displaystyle a = \frac{3}{2} = 1.5\\\\[/tex]
a = 3/2 is the final answer.
You have a Rectangle with sides of 5ft and 8ft; solve for its perimeter and area.
Answer:
Perimeter = 2(l+w) = 2*(5+8) = 26ft
Area = wl = 8*5 = 40
Step-by-step explanation:
pretty sure :)
In Manhattan, there are 15 CoffeeStops per 100,000 people Manhattan has approximately 1,602,000 people How many Coffee Stops are there?
Answer:
Given that 15coffee stops=100,000people
then: x= 1,602,000
100,000×x= 15×1,602,000
100,000x= 24,030,000
100,000x÷100,000= 24,030,000÷100,000
x= 240.3
so therefore there are 240.3 coffee stops if there are 1,602,000
Manhattan has approximately 1,602,000 people. Then the number of coffee shops will be 241.
What are ratio and proportion?A ratio is a collection of ordered integers a and b represented as a/b, with b never equaling zero. A proportionate expression is one in which two items are equal.
In Manhattan, there are 15 CoffeeStops per 100,000 people.
Then the number of coffee shops per person will be
⇒ 15 / 100,000
⇒ 1.5 × 10⁻⁴ coffee shops per person
Manhattan has approximately 1,602,000 people.
Then the number of coffee shops will be
⇒ 1,602,000 × 1.5 × 10⁻⁴
⇒240.3 or 241 coffee shops
Manhattan has approximately 1,602,000 people. Then the number of coffee shops will be 241.
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I need some help please
The answer is A.
A negative x a negative equals a positive so the square root of a negative value cannot be a negative value.
Pls need help
Also making this 10 points so i have 169 points left B)
Answer:
Second and fourth
Step-by-step explanation:
A line is in point-slope form when you write down as [tex]y-y_0=m(x-x_0)[/tex] - do not be distracted by the signs, +1 and +5 can both be written as -(-1) or -(-5) rispectively.
Please helppppp quick
Answer:
option C
Step-by-step explanation:
x + 5 ≤ 13
x + 5 - 5 ≤ 13 - 5
x = ≤ 8
Answer:
x ≤ 8
Step-by-step explanation:
Move all terms not containing x to the right side of the inequality. Then solve for x. :)
It takes 6 hours to clean and detail a luxury car. During the morning of
cleaning, the workers were able to clean for 4 hours. If the variable t stands
for the amount of time the workers have left to clean the windows after lunch,
which of the following units could apply to this variable?
Graph the equation of the line parallel to 2x−y=6 and passing
through (-3, 1). Show work.
Answer:
It's a graph, see the image.
Step-by-step explanation:
Use the equation to find the slope. Use the slope and the point to graph the line.
Write the equation of the line perpendicular to y = 8 - 5z that contains the point (0, 0) . Fill in the slope and y-intercept
The equation of the line perpendicular to y = 8 - 5z is 5x+8y=16.
8y=-5x+16
y=-5/8x+2.
To be perpendicular, the slope has to be 8/5.
What is the slope-intercept form of the line?
The slope-intercept form is y=mx+c
Where m is the slope and c is the y-intercept.
So y=8/5x+b.
We can plug in the given coordinates to get
7=8/5*-5+b
7=-8+b
b=15.
So eqn is y=8/5x+15 or in point-slope form, y=8/5x+15
5y=8x+75
5y-8x=75
The equation of the line perpendicular to y = 8 - 5z is 5x+8y=16.
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Mark’s birthday is 32 weeks away. How many days until his birthday?
NEED NOW PLEASE.....
Answer:
2+(-6)
Step-by-step explanation:
hope this helps
Can someone help me please
Suppose a quadratic equation has the form x^2 + x + c = 0. Show that the constant c must be less than 1/4 in order for the equation to have two real solutions.
Answer:
see explanation
Step-by-step explanation:
Given a quadratic equation in standard form
ax² + bx + c = 0 ( a ≠ 0 )
Then for the equation to have 2 real roots , the discriminant must be greater than zero , that is
b² - 4ac > 0
x² + x + c = 0 ← is in standard form
with a = 1, b = 1, c = c , then
b² - 4ac > 0
1² - (4 × 1 × c) > 0
1 - 4c > 0 ( subtract 1 from both sides )
- 4c > - 1
Divide both sides by - 4, reversing the inequality as a result of dividing by a negative quantity.
c < [tex]\frac{1}{4}[/tex]
Dr. M wanted to estimate the mean cholesterol level for men living in Hartford. He took a sampled of 20 men from Hartford and found that mean cholesterol level is 86 with a standard deviation of 12. He wants to construct a 99 % confidence interval for mean cholesterol level of men.
In this case, the level of significance a and the critical value?
Answer:
answer is in an image here
imageshare.best/image.php?id=JS9NDO
Explanation:
copy n paste in browser
not a bot btw
11. Select the proper order from least to greatest for 2/3, 7/6, 1/8, 9/10.
O A.1/8, 2/3, 9/10, 7/6
O B.2/3, 9/10, 7/6, 1/8
O C.7/6,9/10, 2/3, 1/8
O D. 1/8, 9/10, 7/6, 2/3
Step-by-step explanation:
Option A is the correct answer
Answer:
A is correct
Step-by-step explanation:
[tex]\frac{1}{8}[/tex] is 0.125
[tex]\frac{2}{3}[/tex] is 0.667
[tex]\frac{9}{10}[/tex] is 0.9
[tex]\frac{7}{6}[/tex] is 1.167
which from this you can see that A represents the order from smallest to largest
2. If Jordan's section contains 35 rows, how many seats are in her section?
seat(s)
Answer:
5
Step-by-step explanation:
can anyone help me please just cat get it
Answer:
it is c I think if not sorry
[tex]~\hspace{10em}\textit{function transformations} \\\\\\ \begin{array}{llll} f(x)= A( Bx+ C)^2+ D \\\\ f(x)= A\sqrt{ Bx+ C}+ D \\\\ f(x)= A(\mathbb{R})^{ Bx+ C}+ D \end{array}\qquad \qquad \begin{array}{llll} f(x)=\cfrac{1}{A(Bx+C)}+D \\\\\\ f(x)= A sin\left( B x+ C \right)+ D \end{array} \\\\[-0.35em] ~\dotfill[/tex]
[tex]\bullet \textit{ stretches or shrinks horizontally by } A\cdot B\\\\ \bullet \textit{ flips it upside-down if } A\textit{ is negative}\\ ~~~~~~\textit{reflection over the x-axis} \\\\ \bullet \textit{ flips it sideways if } B\textit{ is negative}\\ ~~~~~~\textit{reflection over the y-axis}[/tex]
[tex]\bullet \textit{ horizontal shift by }\frac{ C}{ B}\\ ~~~~~~if\ \frac{ C}{ B}\textit{ is negative, to the right}\\\\ ~~~~~~if\ \frac{ C}{ B}\textit{ is positive, to the left}\\\\ \bullet \textit{ vertical shift by } D\\ ~~~~~~if\ D\textit{ is negative, downwards}\\\\ ~~~~~~if\ D\textit{ is positive, upwards}\\\\ \bullet \textit{ period of }\frac{2\pi }{ B}[/tex]
now keeping that template for transformations above in mind, let's take a look at this one
[tex]\stackrel{\textit{original}}{f(x) = |x|}\implies f(x)=\stackrel{A}{1}|\stackrel{B}{1}x+\stackrel{C}{0}|+\stackrel{D}{0}[/tex]
now, the vertex of this type, or original that'll be the origin at (0,0), and its' graph looks like a V.
now let's take a peek at the graph, hmmm from the original V-shape it moved to the left by 2 units, with a horizontal shift of C/B = 2, we can say that +2/1 gives B = 1 and C = +2, and moved upwards by 3 units, namely D = +3.
we can also see that it flipped upside-down over the horizontal(x-axis), namely A is negative, on all choices the only value we see for A is "4", so it must be that A = -4
let's plug all those in
[tex]\begin{cases} A=-4\\ B=1\\ C=+2\\ D=+3 \end{cases}\qquad f(x)=\stackrel{A}{-4}|\stackrel{B}{1}x+\stackrel{C}{2}|+\stackrel{D}{3}\implies f(x)=-4|x+2|+3[/tex]
Joshua's assignment this weekend is to read a book with seventy-four pages. On Saturday he read thirty pages. How many pages does he need to read on Sunday?
Answer:
61
Step-by-step explanation:
he read first 74 and need to
= 74-30
=44
Which triangle has vertices (–3, –5), (7, 4), (0, 4)?
Answer:
see attached
Step-by-step explanation:
The one that matches the triangle shown in the attachment has the given vertices.
When divide f(x)=ax³+bx²+cx+d by (x+3), the remainder is 4, then what is the remainder when divide 2f(x)-6 by (x+3)?
Answer:
2Step-by-step explanation:
When divide f(x)=ax³+bx²+cx+d by (x+3), the remainder is 4:
f(x) = m*(x + 3) + 4, where m is the quotientThen 2f(x) - 6 is:
2[m(x + 3) + 4] - 6 = 2m(x + 3) + 8 - 6 = 2m(x + 3) + 2As we see the remainder is 2
Larry is using an online calculator to calculate the outputs f(n) for different inputs n. The ordered pairs below show Larry's inputs and the corresponding outputs displayed by the calculator: (1, 5), (2, 9), (3, 13), (4, 17) Which of the following functions best represents the rule that the calculator uses to display the outputs?
Answer: The answer is c. f(n)=4n+1
can help my little bro
Answer:
$0.03
Step-by-step explanation:
chips: 7.84/16=0.49
pretzels: 12.48/24=0.52
0.52=0.49=0.03
three hundred two times one hundred fifty three
302×153
Answer:
46,206
Step-by-step explanation:
simple math
Answer:
the answer is 46,206
Step-by-step explanation:
Good luck!!!!
Which is a composite number? A.97 B.89 C.95 D.13
PLEASE I REALLY NEED THE CORRECT ANSWER RIGHT NOW!!!!
Answer: C. 95 is a composite number.
Step-by-step explanation:
You can look at the ones place of each number to see if any end in 0, 2, 5, or any other digit that indicates that the number is not prime. Since 95 ends in a 5, it can be divided by 5, making it have more factors than 1 and itself. Therefore, 95 is the composite number of the list of numbers.
Answer:95
Step-by-step explanation:composite numbers are numbers that have more factors than 1 and itself, factors are numbers you can multiply to get a number. 95 is a composite number since 1,95, AND 5 are all factors of 95 making it a composite number
what is the value of x in m(x+n)=n
The equation m(x + n) = n si solved for x will be given as x = n / m (1 - m).
What is the linear system?A linear system is one in which the parameter in the equation has a degree of one. It might have one, two, or even more variables.
The equation is given below.
m(x + n) = n
By simplifying for x, then we have
x + n = n / m
x = n / m - n
x = (n - mn) / m
x = n / m (1 - m)
More about the linear system link is given below.
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6. Your gas tank can hold no more than 14.5 gallons of gasoline. On a trip to the grocery store, you use 1.5 gallons of gasoline. Write and solve an inequality that represents the amount of gasoline left in your gas tank after 2 trips to the grocery store.
Answer:
14.5 ≥ g(1.5)
g = The number of trips to the grocery store.
You will have 11.5 gallons left.
This question on your unit test is a fill in the blank. Be prepared to type your answer. The graph show how many minutes it takes Ziah to run a certain distance in the city. What is the meaning of the point (4, 6)?
The point (4,6) means it took Ziah 4 minutes to run 6 blocks.
This is because any point is of the form (x,y) where in this case
x = number of minutes
y = number of blocks
Kevin will be taking six classes next semester (Algebra, World History, Psychology, Political Science, Chemistry, and Art Theory) and would like to know how many different ways he can order his class schedule given that his university offers six time slots for classes each day. Assuming there are no constraints and each class can be taken in any time slot, how many different ways can Kevin order his classes?
=========================================================
Explanation:
We have 6 slots to fill A,B,C,D,E,F
There are 6 choices for choice A, then 5 choices for slot B, 4 for C, and so on until we reach one choice for slot F. Count down by 1 each time a slot is filled.
Multiply out those values to get: 6*5*4*3*2*1 = 720
For more information, check out the concept of factorials.
---------
Another approach is to use the nPr permutation formula which is
[tex]_nP_r = \frac{n!}{(n-r)!}[/tex]
where in this case n = 6 and r = 6.
Talia’s Australian Shepherd weighed 11 pounds when they first brought him home. By the time he was 6 months old, he weighed 33 pounds. What is the percent increase? *
Answer:
11+ 200% = 33 pounds
The percent increase is 200%
Step-by-step explanation:
What's The Interest Rate?
I = $200
P = $800
T = 24 months
A room has a rectangular floor 5.5 m long and 4.5 m wide. The room is 2.5 m in height.
A. What is the area of wall space in the room?
B. How much paint is required to paint the
walls with two coats if one litre of paint
can cover 11.25 m??
Answer:
Length=8 m,Breadth=6 m,Height=3 m
We know,
LSA=2(l+b)×h
LSA=2×14×3=84 m
2
Therefore, cost of painting = 84×60=Rs.5040.