======================================================
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.
-----------------
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.
-----------------
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.
Exercise on Properties/Laws of Sets Simplify each of the following identities to its simplest form, using the laws of sets; (i) (An B) U (AU B')'
(ii) An (AUB)
(iii) (CUA N (BUA)
Which graph represents a function?
Answer:
just the first on. upper left corner
.
Simplify.
{[2 + 3(−3 – 4) – 3] – 2} ÷ 23
Answer:
-0.2
Step-by-step explanation:
pls give me brainliest if possible
A yoga studio charges a $180 yearly fee for membership plus $18 for each class. What is the average total cost per class if a studio member takes 75 classes per year? Do not include the dollar sign ($) in your answer.
Answer:
Average total cost per class is 13.5
Step-by-step explanation:
A yoga studio charges a 150 yearly fee for membership plus150yearlyfeeformembershipplus12 for each class.
Yearly charge = 150 $
Charge per class = 12 $
A studio member takes 100 classes per year
Number of class attended by studio member = 100
We need to find average total cost per class for this member for a year.
Total charge = Yearly charge + Number of class attended x Charge per class
Total charge = 150 + 100 x 12
Total charge = 150 + 1200
Total charge = 1350 $
\begin{gathered}\texttt{Average total cost per class = }\frac{\texttt{Total charge}}{\texttt{Number of class attended by studio member}}\\\\\texttt{Average total cost per class = }\frac{1350}{100}=13.5\$\end{gathered}
Average total cost per class =
Number of class attended by studio member
Total charge
Average total cost per class =
100
1350
=13.5$
Average total cost per class = 13.5 $
Study hard
Brainliest please thank you!
Answer:
1,530
Step-by-step explanation:
Total charge = 180 + 75 x 18
Total charge = 150 + 1,350
Total charge = 1,530 $
whats 3-6h if h = -1
Answer:
9 is the answer.
Step-by-step explanation:
Given:
h = -1=> 3-6h
=> 3 - 6(-1)
=> 3 + 6
=> 9
Therefore, 9 is the answer.
Hoped this helped.
Slove the followings.
1. Use your calculator to work out the weight of rubbish in each category.
2. A household produces 1.2 t of rubbish in a year. How many adults live in the house?
3. a. How much rubbish would an adult produce in a year if he recycled the glass, paper, and card?
b. What if he also had a compost heap at foot of his garden for vegetable and decomposable material?
2. The number of adults who live in the house is 3 (1,200/400).
3.a. If an adult recycled the glass, paper, and card that have 42% of the rubbish, the adult will generate 232 kg (400 kg x (1 - 42%) of rubbish.
b. If the adult, in addition, had a composite for vegetable and decomposable material, he will generate 152 kg (400 kg x (1 - 62%).
Data and Calculations:
1 ton = 1,000 kg
Weight of rubbish produced by an adult per year = 400 kg
Total kg of rubbish produced by the family = 1,200 kg (1,000 x 1.2)
Percentage of Vegetable and decomposable material = 20%
Percentage of glass, paper, and card = 42% (33% + 9%)
Learn more: https://brainly.com/question/14954924
-35.9=y/0.1+0.1 please help me with this.
Answer:
358.9 I think
Step-by-step explanation:
What is 15/4 as a decimal?
Answer:
3.75
Step-by-step explanation:
Answer: 3.34
REEEEEEEEEEEEEEEEEEEEEEEEE
Melanie was training for a race. The line plot below shows the number of miles Melanie ran last week.
2. How many times did Melanie run ½ a mile?
Answer:
5 miles
Step-by-step explanation:
add the points together.
it seems like each point is how many miles they ran each day.
1/4 + 2(1/2) + 3/4 + 3(1) = 5
. In a study of air-bag effectiveness it was found that in 821 crashes of midsize cars equipped with air bags, 46 of the crashes resulted in hospitalization of the drivers (based on data from the highway Loss Data Institute). Using a 0.01 significance level, you need to test the claim that the air-bag hospitalization rate is lower than the 7.8% rate for crashes of mid-size cars equipped with automatic safety belts. What conclusion should you make
Answer:
P(X ≤ 46 | X~B(821, 0.078)) = 0.00885745584
0.00885... < 0.01
The test statistic of 46 is significant
There is sufficient evidence to reject H₀ and accept H₁
Air bags are more effective as protection than safety belts
Step-by-step explanation:
821 crashes
46 hospitalisations where car has air bags
7.8% or 0.078 probability of hospitalisations in cars with automatic safety belts
α = 0.01 or 1% ← level of significance
One-tailed test
We are testing whether hospitalisations in cars with air bags are less likely than in a car with automatic safety belts;
The likelihood of hospitalisation in a car with automatic safety belts, we are told, is 7.8% or 0.078;
So we are testing if hospitalisations in cars with air bags is less than 0.078;
So, firstly:
Let X be the continuous random variable, the number of hospitalisations from a car crash with equipped air bags
X~B(821, 0.078)
Null hypothesis (H₀): p = 0.078
Alternative hypothesis (H₁): p < 0.078
According to the information, we reject H₀ if:
P(X ≤ 46 | X~B(821, 0.078)) < 0.01
To find P(X ≤ 46) or equally P(X < 47), it could be quite long-winded to do manually for this particular scenario;
If you are interested, the manual process involves using the formula for every value of x up to and including 46, i.e. x = 0, x = 1, x = 2, etc. until x = 46, the formula is:
[tex]P(X = r) = nCr * p^{r} * (1 - p)^{n - r}[/tex]
You can find binomial distribution calculators online, where you input n (i.e. the number of trials or 821 in this case), probability (i.e. 0.078) and the test statistic (i.e. 46), it does it all for you, which gives:
P(X ≤ 46 | X~B(821, 0.078)) = 0.00885745584
Now, we need to consider if the condition for rejecting H₀ is met and recognise that:
0.00885... < 0.01
There is sufficient evidence to reject H₀ and accept H₁.
To explain what this means:
The test statistic of 46 is significant according to the 1% significance level, meaning the likelihood that only 46 hospitalisations are seen in car crashes with air bags in the car as compared to the expected number in car crashes with automatic safety belts is very unlikely, less than 1%, to be simply down to chance;
In other words, there is 99%+ probability that the lower number of hospitalisations in car crashes with air bags is due to some reason, such as air bags being more effective as a protective implement than the safety belts in car crashes.
{x|x is an odd integer between -3 and 7}
Answer:
x={-1,1,3,5}
Step-by-step explanation:
x={-1,1,3,5}
The quotient of 2 numbers, p and q
A: pq
B: p+q
C: p/q
D: p - q
Answer:
b
Step-by-step explanation:
pls pls pls mark me as brainliest
Answer:
C: p/q
Step-by-step explanation:
Quotient is the result of dividing two numbers so C would be the best answer
Hope this helps! :D
Which is NOT true?
7 + 7 = 19 - 5
9 + 9 = 11 + 7
19 = 13 + 5
20 - 12 = 4 + 4
Answer:
c.19 = 13 + 5
Step-by-step explanation:
The domain of y = cosx is the set of real numbers. True False
Answer:
true
Step-by-step explanation:
Simplify.
57.8 – 4.07
Answer:
53.73
Step-by-step explanation:
he .......... be eating pizza.
He will be eating pizza
S + will + be + V_ing
PLEASE HELP! WILL MARK BARINLIEST IF ANSWER CORRECTLY (Screenshot)
Answer:
14
Step-by-step explanation:
3+3+4+4 = 14
4. If Il k and k // m, then
if
t // kk // mthen t // m is correct answerbcaz according to property of transitivity
An example of a transitive law is “If a is equal to b and b is equal to c, then a is equal to c.” There are transitive laws for some relations but not for others. A transitive relation is one that holds between a and c if it also holds between a and b and between b and c for any substitution of objects for a, b, and c.
Solve x2 + 5x – 3 = 0 using the quadratic formula.
Solve (2x – 1)2 = 8 using the quadratic formula.
A) x = –1∕2 + , x = –1∕2 –
B) x = 1∕2 + , x = 1∕2 –
C) x = 1∕2
D) x = –1∕2
Answer:
d
Step-by-step explanation:
distribute two through the parentheses
=4x-2
move the constant to the right side and change its sign
=4x=8+2
=4x=10
divide both sides by 4
x=5/2
I need help with pre calculus.
Problem 1
Answer: Choice A. (0,9)---------------------
Explanation:
The first task is to determine the function for f(x). Because it's linear, it's in the form y = mx+b. Let's find the slope m.
Select any two columns to pick out (x,y) points from the f(x) function. I'll pick the first two columns to select the points (-6,15) and (-4,11). Apply the slope formula to these two points to get...
m = (y2-y1)/(x2-x1)
m = (11-15)/(-4-(-6))
m = (11-15)/(-4+6)
m = -4/2
m = -2
Then use this m value along with any of the points of the table to determine the y intercept b. I'll use the point (-6,15)
y = mx+b
b = y-mx
b = 15-(-2)*(-6)
b = 15-12
b = 3
The y = mx+b equation becomes y = -2x+3 and that leads directly to the function f(x) = -2x+3.
Repeat all of those steps but do so for g(x) this time. I'll skip those steps over but you should get the function g(x) = 5x-6.
The y intercepts of f(x) and g(x) found were 3 and -6 respectively. Subtract those values to find the y intercept of h(x) = (f-g)(x) = f(x)-g(x).
So we get 3-(-6) = 3+6 = 9 which leads to the location (0, 9).
=========================================================
Problem 2
Answer: Choice Ax is any real number but x cannot equal -2, -1 or 1.---------------------
Explanation:
Through trial and error, the factor by grouping method, or using your graphing calculator, factor the denominator to get
g(x) = x^3+2x^2-x-2 = (x+2)(x+1)(x-1)
The factors (x+2), (x+1) and (x-1) lead to the roots of x = -2, x = -1, and x = 1 in that order. Those three roots of g(x) will make g(x) = 0 and cause a division by zero error in the denominator. So we must kick out those three values from the domain. Every other real number is allowed in the domain. So that's how we get the notation for choice A. It starts off saying x is a real number. Then it goes onto say that -2, -1 and 1 aren't allowed.
So overall the domain is described as: "x can be almost any real number except x cannot be -2, cannot be -1, and it cannot be 1".
Side note: We don't involve the numerator function at all.
=========================================================
Problem 3
Answer: Choice B. 2x+1 and x-3---------------------
Explanation:
The height is x, which we can factor out like this
2x^3-5x^2-3x
2x^2*x - 5x*x - 3*x
x(2x^2-5x-3)
Effectively you would use the distribution rule in reverse.
Now let's factor the remaining expression in the parenthesis.
I'll use the factor by grouping method.
2x^2-5x-3
2x^2-6x+1x-3
(2x^2-6x) + (1x-3)
2x(x-3) + 1(x-3)
(2x+1)(x-3)
Therefore, the full factorization is
x(2x+1)(x-3)
which shows we have the dimensions of x, (2x+1) and (x-3). The order doesn't matter so we could easily have (2x+1) the length and (x-3) the width, or we could have it the other way around.
You can verify that (2x+1)(x-3) expands out to 2x^2-5x-3 using either the FOIL method or the box method.
A group hiked 3 7/10 miles on the Blue Trail and then 4 3/4 miles on the White Trail. What is the total distance the group hiked?
Answer:
8 9/20
Step-by-step explanation:
Just add them which would give you 169/20 and then simplify it which would be 8 9/20.
3] What is - 2y + 10 + 2y - 8 simplified?
a) – 4y + 18
C) 18
b) 4y + 2
d) 2
Expressions
Answer:
d. 2
Step-by-step explanation:
-2y +10+2y-8
10-8. ( -2y+2y = 0)
2
Answer:
d) 2
Step-by-step explanation:
We can first combine like terms
-2y + 2y = 0
Now, our expression is simply 10 - 8, which is 2
So, the answer is
d) 2
I need help with this one. I will give someone brainliest.
3a+5=20 steps on paper
Answer:
5
Step-by-step explanation:
3a+5=20 -5
3a=15 /3
a=5
Rewrite each of the following terms as an extended product. Consider carefully your order of operations and remember that exponents come before multiplication. You do not need to simplify the products.
#a
[tex]\\ \sf{:}\dashrightarrow 4^3=(2\times 2)^3=2^6[/tex]
#b
[tex]\\ \sf{:}\dashrightarrow 3^2.3^3=3^5[/tex]
#c
[tex]\\ \sf{:}\dashrightarrow (2^3)^4=2^{12}[/tex]
#d
[tex]\\ \sf{:}\dashrightarrow x^3y^4\checkmark[/tex]
#e
[tex]\\ \sf{:}\dashrightarrow 8x^2y^5=2^3x^2y^5[/tex]
#f
[tex]\\ \sf{:}\dashrightarrow( 9x^2)^2=(3^2x^2)^2=3^4x^4[/tex]
Planes A and B are shown.
If a new line, p, is drawn parallel to line I, which
statement is true?
ZA
O Line p must be drawn in plane B.
O Line p must be perpendicular to line m.
O Line p must be drawn so that it can lie in the same
plane as line 1
O Line p must be drawn in the same plane as line n.
m
find the solution to the following system using substitution. y = - 4 + 9 y = 3x - 5
Answer:
1/2, 11/6
Step-by-step explanation:
y=-4+9y
9y-y=4
8y=4
y=1/2
3x-5=1/2
3x=5+1/2=11/2
x=11/6
35 devide 28 with decimals pls help
Answer:
1.25
Step-by-step explanation:
The answer in decimal is 1.25
35/28= 1.25
= 35 ÷ 28
by 1
=35 - 28 = 7
Introducing decimals
= 70 to 28
by 2
= 70 - 56 = 14
adding zero to 14
= 140 to 28
by 5
= 140 - 140 =0
the answer is 1.25
I did it this way through division hope you'll understand. All the best.
Please help. Due in 30 mins!!
1: 1.645
2. 1.28
4: 95% confidence level (12.93, 13.87)
3: No Idea
5: sorry im a bit rusty
Im so sorry for not answering all you questions
y<-2/3 x-1 graphing the inequality
Answer:
y < − 2/3x − 1
Step-by-step explanation:
