Suppose that X; Y have constant joint density on the triangle with corners at (4; 0), (0; 4), and the origin. a) Find P(X < 3; Y < 3). b) Are X and Y independent
The triangle (call it T ) has base and height 4, so its area is 1/2*4*4 = 8. Then the joint density function is
[tex]f_{X,Y}(x,y)=\begin{cases}\frac18&\text{for }(x,y)\in T\\0&\text{otherwise}\end{cases}[/tex]
where T is the set
[tex]T=\{(x,y)\mid 0\le x\le4\land0\le y\le4-x\}[/tex]
(a) I've attached an image of the integration region.
[tex]P(X<3,Y<3)=\displaystyle\int_0^1\int_0^3f_{X,Y}(x,y)\,\mathrm dy\,\mathrm dx+\int_1^3\int_0^{4-x}f_{X,Y}(x,y)\,\mathrm dy\,\mathrm dx=\frac12[/tex]
(b) X and Y are independent if the joint distribution is equal to the product of their marginal distributions.
Get the marginal distributions of one random variable by integrating the joint density over all values of the other variable:
[tex]f_X(x)=\displaystyle\int_{-\infty}^\infty f_{X,Y}(x,y)\,\mathrm dy=\int_0^{4-x}\frac{\mathrm dy}8=\begin{cases}\frac{4-x}8&\text{for }0\le x\le4\\0&\text{otherwise}\end{cases}[/tex]
[tex]f_Y(y)=\displaystyle\int_{-\infty}^\infty f_{X,Y}(x,y)\,\mathrm dx=\int_0^{4-y}\frac{\mathrm dx}8=\begin{cases}\frac{4-y}8&\text{for }0\le y\le4\\0&\text{otherwise}\end{cases}[/tex]
Clearly, [tex]f_{X,Y}(x,y)\neq f_X(x)f_Y(y)[/tex], so they are not independent.
The expression $16x^2-106x-105$ can be written as $(8x + a)(2x + b),$ where $a$ and $b$ are integers. What is $a + 2b$?
Answer:
-23
Step-by-step explanation:
16x² - 106x - 105
factoring X
14 x -120 = -1680
14 - 120 = -106
16x² + 14x - 120x - 105
(16x² + 14x) -(120x - 105)
factor out 2 and -15 to get the same expression (8x + 7)
2x(8x + 7) - 15(8x + 7)
(8x + 7)(2x - 15)
a = 7
b = -15
a + 2b
7 + (-15 x 2)
7 + (-30)
= -23
Pablo rented a truck for one day. There was a base fee of $19.99, and there was an additional charge of 80 cents for each mile driven. Pablo had to pay
$221.59 when he returned the truck. For how many miles did he drive the truck?
Answer:
252 miles
Step-by-step explanation:
19.99 + .80x = 221.59
,80x = 201.60
x = 252
A train goes at a speed of 70km / h. If it remains constant at that speed, how many km will it travel in 60 minutes?
Answer:
Total distance travel by train = 70 km
Step-by-step explanation:
Given:
Speed of train = 70 km/h
Total time taken = 60 min = 60 / 60 = 1 hour
Find:
Total distance travel by train
Computation:
Distance = Speed × Time
Total distance travel by train = Speed of train × Total time taken
Total distance travel by train = 70 × 1
Total distance travel by train = 70 km
area to the right of z=0.72
I don’t have a graphing calculator and I couldn’t find one online. I’m completely clueless on this one.
Answer:
Desmos could come in handy
24. After a vertical reflection across the x-axis, f(x) is
Options:
A. –f(x)
B. f(x – 1)
C. –f(–x)
D. f(–x)
Answer:
A. –f(x)
Step-by-step explanation:
The transformation of a reflection about the x-axis is
f(x) -> -f(x).
So the answer is
A. –f(x)
You are an urban planner assessing the growth of a city. Ten years ago, the city's population was 250,823. Its current population is 325,823. By about what percentage has the city grown over the past ten years? Round to the nearest percent.
Answer:
I just answered it
Step-by-step explanation:
What's the exact value of tan 15°?
Answer:
The answer is 0.267949192
Step-by-step explanation:
I hope that is enough numbers.
PLEASE HELP!!! (1/5) - 50 POINTS-
Answer:
consistent independent
Step-by-step explanation:
This is a graph of consistent independent equations
The lines cross and there is one solution
Inconsistent equations never cross and there is no solutions
Consistent dependent equations are equations of the same line
Answer:
Linear
Step-by-step explanation:
This is a graph of linear system of equation.
The two lines represent different equations connected with each other.
They intersect at a common point showing the solution to the system of equation.
Nina skated for 2 hours and 14 min she stop at 8:24 pm when did Nina start skating
Answer:
6:10 pm
Step-by-step explanation:
she skate for 2 h and 14 min so,
8:24- 2:14
=6:10 pm
i will rate you brainliest
Answer:
Option (3)
Step-by-step explanation:
For a geometric progression,
[tex]a,ar,ar^{2},ar^3.........a(r)^{n-1},a(r)^n[/tex]
First term of the progression = a
Common ratio of each successive term to the previous term = r
Recursive formula for geometric progression will be,
[tex]a_1=a[/tex]
And [tex]a_{n}=a_{n-1}(r)[/tex]
Following this rule for the G.P. given in the question,
[tex]a_1=4[/tex]
[tex]a_n=-1.5a_{n-1}[/tex]
Therefore, from the recursive formula,
Common ration 'r' = -(1.5)
Option (3) will be the correct option.
the ration of men to women in a certain factory is 3 to 4. there are 204 men. how many workers are there?
Answer:
476 workers
Step-by-step explanation:
Men: women : total
3 4 3+4 = 7
We want 204 men
204/3 =68
Multiply each by 68
Men: women : total
3*68 4*68 7*68
204 272 476
Answer:
There are 476 workers
Step-by-step explanation:
An evergreen nursery usually sells a certain shrub after 9 years of growth and shaping. The growth rate during those 9 years is approximated by
dh/dt = 1.8t + 3,
where t is the time (in years) and h is the height (in centimeters). The seedlings are 10 centimeters tall when planted (t = 0).
(a) Find the height after t years.
h(t) =
(b) How tall are the shrubs when they are sold?
cm
Answer:
(a) After t years, the height is
18t² + 3t + 10
(b) The shrubs are847 cm tall when they are sold.
Step-by-step explanation:
Given growth rate
dh/dt = 1.8t + 3
dh = (18t + 3)dt
Integrating this, we have
h = 18t² + 3t + C
When t = 0, h = 10cm
Then
10 = C
So
(a) h = 18t² + 3t + 10
(b) Because they are sold after every 9 years, then at t = 9
h = 18(9)² + 3(9) + 10
= 810 + 27 + 10
= 847 cm
Suppose that Y1, Y2,..., Yn denote a random sample of size n from a Poisson distribution with mean λ. Consider λˆ 1 = (Y1 + Y2)/2 and λˆ 2 = Y . Derive the efficiency of λˆ 1 relative to λˆ 2.
Answer:
The answer is "[tex]\bold{\frac{2}{n}}[/tex]".
Step-by-step explanation:
considering [tex]Y_1, Y_2,........, Y_n[/tex] signify a random Poisson distribution of the sample size of n which means is λ.
[tex]E(Y_i)= \lambda \ \ \ \ \ and \ \ \ \ \ Var(Y_i)= \lambda[/tex]
Let assume that,
[tex]\hat \lambda_i = \frac{Y_1+Y_2}{2}[/tex]
multiply the above value by Var on both sides:
[tex]Var (\hat \lambda_1 )= Var(\frac{Y_1+Y_2}{2} )[/tex]
[tex]=\frac{1}{4}(Var (Y_1)+Var (Y_2))\\\\=\frac{1}{4}(\lambda+\lambda)\\\\=\frac{1}{4}( 2\lambda)\\\\=\frac{\lambda}{2}\\[/tex]
now consider [tex]\hat \lambda_2[/tex] = [tex]\bar Y[/tex]
[tex]Var (\hat \lambda_2 )= Var(\bar Y )[/tex]
[tex]=Var \{ \frac{\sum Y_i}{n}\}[/tex]
[tex]=\frac{1}{n^2}\{\sum_{i}^{}Var(Y_i)\}\\\\=\frac{1}{n^2}\{ n \lambda \}\\\\=\frac{\lambda }{n}\\[/tex]
For calculating the efficiency divides the [tex]\hat \lambda_1 \ \ \ and \ \ \ \hat \lambda_2[/tex] value:
Formula:
[tex]\bold{Efficiency = \frac{Var(\lambda_2)}{Var(\lambda_1)}}[/tex]
[tex]=\frac{\frac{\lambda}{n}}{\frac{\lambda}{2}}\\\\= \frac{\lambda}{n} \times \frac {2} {\lambda}\\\\ \boxed{= \frac{2}{n}}[/tex]
Please help! Stuck on this question!!
Answer:
The 2 Gallon Tank is Enough
Step-by-step explanation:
A drink bottler needs to bottle 16 one-pint bottles. He has a 2 gallon tank and a 3 gallon tank.
There are 8 pints in a gallon. This means that 2 gallons would be 16 pints.
[tex]8 * 2 = 16[/tex]
So, the 2 gallon tank has 16 pints, which means that the 2 gallon tank should be enough to bottle all 16 bottles.
Answer:
2 gallon tank
Step-by-step explanation:
16 pints is the same as 2 US gallons
Find the domain of the Bessel function of order 0 defined by [infinity]J0(x) = Σ (−1)^nx^2n/ 2^2n(n!)^2 n = 0
Answer:
Following are the given series for all x:
Step-by-step explanation:
Given equation:
[tex]\bold{J_0(x)=\sum_{n=0}^{\infty}\frac{((-1)^{n}(x^{2n}))}{(2^{2n})(n!)^2}}\\[/tex]
Let the value a so, the value of [tex]a_n[/tex] and the value of [tex]a_(n+1)[/tex]is:
[tex]\to a_n=\frac{(-1)^2n x^{2n}}{2^{2n}(n!)^2}[/tex]
[tex]\to a_{(n+1)}=\frac{(-1)^{n+1} x^{2(n+1)}}{2^{2(n+1)}((n+1))!^2}[/tex]
To calculates its series we divide the above value:
[tex]\left | \frac{a_(n+1)}{a_n}\right |= \frac{\frac{(-1)^{n+1} x^{2(n+1)}}{2^{2(n+1)}((n+1))!^2}}{\frac{(-1)^2n x^{2n}}{2^{2n}(n!)^2}}\\\\[/tex]
[tex]= \left | \frac{(-1)^{n+1} x^{2(n+1)}}{2^{2(n+1)}((n+1))!^2} \cdot \frac {2^{2n}(n!)^2}{(-1)^2n x^{2n}} \right |[/tex]
[tex]= \left | \frac{ x^{2n+2}}{2^{2n+2}(n+1)!^2} \cdot \frac {2^{2n}(n!)^2}{x^{2n}} \right |[/tex]
[tex]= \left | \frac{ x^{2n+2}}{2^{2n+2}(n+1)^2 (n!)^2} \cdot \frac {2^{2n}(n!)^2}{x^{2n}} \right |\\\\= \left | \frac{x^{2n}\cdot x^2}{2^{2n} \cdot 2^2(n+1)^2 (n!)^2} \cdot \frac {2^{2n}(n!)^2}{x^{2n}} \right |\\\\[/tex]
[tex]= \frac{x^2}{2^2(n+1)^2}\longrightarrow 0 <1[/tex] for all x
The final value of the converges series for all x.
The screening process for detecting a rare disease is not perfect. Researchers have developed a blood test that is considered fairly reliable. It gives a positive reaction in 94.8% of the people who have that disease. However, it erroneously gives a positive reaction in 3.3% of the people who do not have the disease. Consider the null hypothesis "the individual does not have the disease" to answer the following questions.
a. What is the probability of Type I error?
b. What is the probability of Type II error?
Answer:
Probability of Type 1 error = 0.033
Probability of type II error = 0.952
Step-by-step explanation:
H0: Individual does not have disease
H1: individual has disease
Type 1 error occurs when we fail to accept a correct null hypothesis and accept an alternate Instead
Type ii error occurs when we accept a false null hypothesis instead of the alternate hypothesis
Probability of people with disease = 98.4%
Probability of people without disease = 3.3%
1.probability of type 1 error = 3.3/100
= 0.033
2. Probability of type ii error = (1-98.4%) = 1-0.948
= 0.052
Circle O has a circumference of 36π cm. Circle O with radius r is shown. What is the length of the radius, r? 6 cm 18 cm 36 cm 72 cm
Answer:
18 cm.
Step-by-step explanation:
The circumference of a circle is found by calculating 2 * pi * r.
In this case, the circumference is 36 pi cm.
2 * pi * r = 36 * pi
2 * r = 36
r = 36 / 2
r = 18 cm.
Hope this helps!
Answer:
18 centimeters
Step-by-step explanation:
The circumference of a circle can be found using the following formula.
[tex]c=2\pi r[/tex]
We know the circumference is 36π cm, therefore we can substitute 36π in for c.
[tex]36\pi= 2 \pi r[/tex]
We want to find r, the radius. Therefore, we must get r by itself. First, divide both sides of the equation by pi.
[tex]36\pi / \pi = 2 \pi r / \pi\\\\36= 2 \pi r / \pi\\\\36=2r[/tex]
Next, divide both sides of the equation by 2.
[tex]36=2r \\\\36/2=2r/2\\\\36/2=r\\\\18=r\\\\r=18 cm[/tex]
The radius of Circle O is 18 centimeters.
What expression is equal to6 e + 3 (e-1)
Answer:
9e -3
Step-by-step explanation:
Perform the indicated multiplication:
6 e + 3 (e-1) = 6e + 3e - 3
This, in turn, simplifies to
9e -3, or 3(3e - 1).
Answer:
ANSWER: 9e-3
Step-by-step explanation:
6e+3(e−1)
As we need to simplify the above expression:
First we open the brackets :
3(e-1)=3e-33(e−1)=3e−3
Now, add it to 6e.
So, it becomes,
$$\begin{lgathered}6e+3e-3\\\\=9e-3\end{lgathered}$$
Hence, equivalent expression would be 9e-3.
4.9x10^_8 In decimal notation
Answer:
490000000
Step-by-step explanation:
For every exponent of 10, move the decimal point one place to the right.
I really need help please answer!
Answer:
-2, b, a+c
Step-by-step explanation:
Answer:
-2, b, a+c
Step-by-step explanation:
By looking at where A and C are on the number line, we can tell that A is a negative number close to zero and C is a positive number a little greater than four. This means that if we add the two together, we'll get a positive number a little below four.
By looking at the number line, we can tell that the value of B is a positive number a little below the number three.
Now that we know that B is less than A+C, and we know where -2 is on the number line (two marks to the left of zero) we can decide the least to greatest values.
Since negatives are always less than positives, we know that -2 has the smallest value. Next, we know that B is lower on the number line than A+C. So, in order, from least to greatest, the answer is:
-2, B, A+B
Hope this helps!! <3 :))
A line passes through A(3,7) and B(-4,9). Find the value of a if C(a, 1) is on the line.
Answer: a=24
Step-by-step explanation:
Lets find the line's formula (equation of the line).
As known the general formula of any straight line (linear function) is
y=kx+b
Lets find the coefficient k= (Yb-Ya)/(Xb-Xa)=(9-7)/(-4-3)=-2/7
(Xb;Yb)- are the coordinates of point B
(Xa;Ya) are the coordinates of point A
Now lets find the coefficient b. For this purpose we gonna use the coordinates of any point A or B.
We will use A
7=-2/7*3+b
7=-6/7+b
b=7 6/7
So the line' s equation is y= -2/7*x+7 6/7
Now we gonna find the value of a usingcoordinates of point C.
Yc=1, Xc=a
1=-2/7*a+7 6/7
2/7*a= 7 6/7-1
2/7*a=6 6/7
(2/7)*a=48/7
a=48/7: (2/7)
a=24
Answer:
a=24
Step-by-step explanation:
What would the 60 is x% of 12. Find the value of x.
Answer:
The value of x= 20
Step-by-step explanation:
I believe the question is ,"60% of x is us, find x"
So , if the percentage of x to 60 is 12.
60/100 * x = 12
0.6 *x = 12
Dividing both sides by 0.6
X= 12/0.6
X= (12/6) *(10)
X= 2*10
.x= 20
The value of x= 20
Use the equation p=6k+12 to find the value of p when k=9.
Answer:
66
Step-by-step explanation:
when you plug in 9 for k. you do 6(9) which is 54. then add 12 to 54 and thats ur answer, 66.
What is 1/3 of 675 is left
Brandon is paid 150% of his regular hourly rate for overtime hours. He is paid \$45.00 an hour for overtime hoursWhat is his regular hourly rate?
Answer:
Regular hourly rate for Brandon is $30
Step-by-step explanation:
Let the payment for regular hours be $x
given that
Brandon is paid 150% of his regular hourly rate for overtime hours
payment for overtime hours = 150% of payment for regular hours
payment for overtime hours = 150/100 * x = 3x/2
Given that He is paid \$45.00 an hour for overtime hours
thus,
3x/2 = 45
=> x = 45*2/3 = 30
Thus, regular hourly rate for Brandon is $30
In a school, there are 25% fewer 11th graders than 10th graders, and 20% more 11th graders than 12th graders. The total number of students in 10th, 11th, and 12th grades in the school is 190. How many 10th graders are there at the school?
Answer:
There are 80 10th graders in the school
Step-by-step explanation:
Let the number of 10th graders be x
There are 25% fewer 11th graders
That mean x - 25% of x
x -0.25x = 0.75x
There are 20% more 11th graders than 12th graders
So if number of 12th graders = y, then
0.75x = y + 20/100 * y = y + 0.2y = 1.2y
Since ;
0.75x = 1.2y
then y = 0.75x/1.2 = 0.625x
So let’s add all to give 190
x + 0.75x + 0.625x = 190
2.375x = 190
x = 190/2.375
x = 80
sorry to keep asking questions
Answer:
y = [tex]\sqrt[3]{x-5}[/tex]
Step-by-step explanation:
To find the inverse of any function you basically switch x and y.
function = y = x^3 + 5
Now we switch x and y
x = y^3 +5
Solve for y,
x - 5 = y^3
switch sides,
y^3 = x-5
y = [tex]\sqrt[3]{x-5}[/tex]
Answer:
[tex]\Large \boxed{{f^{-1}(x)=\sqrt[3]{x-5}}}[/tex]
Step-by-step explanation:
The function is given,
[tex]f(x)=x^3 +5[/tex]
The inverse of a function reverses the original function.
Replace f(x) with y.
[tex]y=x^3 +5[/tex]
Switch variables.
[tex]x=y^3 +5[/tex]
Solve for y to find the inverse.
Subtract 5 from both sides.
[tex]x-5=y^3[/tex]
Take the cube root of both sides.
[tex]\sqrt[3]{x-5} =y[/tex]
Use the given data to find the minimum sample size required to estimate the population proportion. Margin of error: 0.028; confidence level: 99%; p and q unknown
Answer:
The minimum sample size is [tex]n = 2123[/tex]
Step-by-step explanation:
From the question we are told that
The margin of error is [tex]E = 0.028[/tex]
Given that the confidence level is 99% then the level of significance is evaluated as
[tex]\alpha = 100 - 99[/tex]
[tex]\alpha = 1 \%[/tex]
[tex]\alpha =0.01[/tex]
Next we obtain the critical value of [tex]\frac{ \alpha }{2}[/tex] from the normal distribution table
The value is [tex]Z_{\frac{ \alpha }{2} } = 2.58[/tex]
Now let assume that the sample proportion is [tex]\r p = 0.5[/tex]
hence [tex]\r q = 1 - \r p[/tex]
=> [tex]\r q = 0.50[/tex]
Generally the sample size is mathematically represented as
[tex]n =[ \frac{Z_{\frac{ \alpha }{2} }}{ E} ]^2 * \r p * \r q[/tex]
[tex]n =[ \frac{2.58}{ 0.028} ]^2 * 0.5 * 0.5[/tex]
[tex]n = 2123[/tex]
find the slope of the line that passes through the two points (0,1) and (-8, -7)
Answer:
The slope of the line is 1Step-by-step explanation:
The slope of a line is found by using the formula
[tex]m = \frac{y2 - y1}{x2 - x1} [/tex]
where
m is the slope and
(x1 , y1) and ( x2 , y2) are the points
Substituting the above values into the above formula we have
Slope of the line that passes through
(0,1) and (-8, -7) is
[tex]m = \frac{ - 7 - 1}{ - 8 - 0} = \frac{ - 8}{ - 8} = 1[/tex]
The slope of the line is 1Hope this helps you
