g Let the joint probability density function of random variables X and Y. (a) Calculate the marginal probability densities of X and Y . (b) Calculate the expected values of X and Y . be given by

Answer:

The standard error of the estimated difference is of 0.0313.

Step-by-step explanation:

To solve this question, we need to understand the central limit theorem, and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

Brand A:

33 out of 197, so:

[tex]p_A = \frac{33}{197} = 0.1675[/tex]

[tex]s_A = \sqrt{\frac{0.1675*0.8325}{197}} = 0.0266[/tex]

Brand B:

25 out of 290, so:

[tex]p_B = \frac{25}{290} = 0.0862[/tex]

[tex]s_B = \sqrt{\frac{0.0862*0.9138}{290}} = 0.0165[/tex]

What would be the standard error of the estimated difference?

[tex]s = \sqrt{s_A^2+s_B^2} = \sqrt{0.0266^2+0.0165^2} = 0.0313[/tex]

The standard error of the estimated difference is of 0.0313.

Find the amount of the increase:

27800 - 23400 = 4,400

Find number of years: 2012 - 2008 = 4 years

Divide amount of change by number of years:

4,400 / 4 = 1,100 people per year.

A number multiplied by a sum is the same as the sum of the number multiplied by each addend; a(b + c) = ab + ac

Answer:

the distributive property of binary operations generalizes the distributive law from elementary algebra, which asserts that one has always For example, one has One says that multiplication distributes over addition.

The answer is prime! I hope this helps you out!

Answer:

23 is a prime number. Reason: Prime number are those numbers which are divisible by 1 and itself. Example: 5 is divisible by 1 and 5 only.

Answer:

Break even sales = $17,500 (Approx.)

Step-by-step explanation:

Given:

Fixed expenses = $7,000

Contribution ratio = 40%

Find:

Break even sales dollars

Computation:

Break even sales = Fixed expenses / Contribution ratio

Break even sales = 7,000 / 40%

Break even sales = 7,000 / 0.40

Break even sales = 17,500

Break even sales = $17,500 (Approx.)

Answer:

c=0

Step-by-step explanation:

ATQ a.b=|a||b|sin(45)

1+c=sqrt(1+c^2)*sqrt(2)*1/sqrt(2)

1+c=sqrt(1+c^2)

(1+c)^2=(1+c^2)

2c=0, c=0

The required simplified value of c is zero for which the angle between a and b is 45°.

Vector is defined as the quantities that have both magnitude and direction are called a vector quantity and the nature of the quantity is called a vector.  

Here,
scaler product is given as,
a . b = |a|.|b|cos45
(i + cj). (i + j) = √[1² + c²] . √[1²+1²] × 1/√2
1 + c = √1 + c²

Squaring both sides
(1 + c)² = 1 + c²
1 + c² + 2c =1 + c²
2c = 0
c = 0

Thus, the required simplified value of c is zero for which the angle between a and b is 45°.

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Answer:

n=1

Step-by-step explanation:

-36 = 6(2-8n)

-36=12-48n

-36-12=-48n

-48=-48n

n=1

Answer:

29/3 is your answer

Step-by-step explanation:

pls mark as brainliest

Step-by-step explanation:

-4b-24-2b+8b2

8b2-6b-24=0

Answer:

missing side length is 12

Step-by-step explanation:

similar means that all correlating pairs of sides have the same ratio (old side length) / (new side length).

so, when we know the ratio of one pair, we can apply it to any other side to calculate the correlating side.

we see, when we go from small to large, that we have the ratio 32/40 = 4/5.

so, multiplying the larger side by this, we get the shorter side.

15 × 4/5 = 3 × 4 = 12

the proportion part in your picture is a bit confusing :

yes,

x/15 = 32/40 = 32/40

I don't know, why this last expression was repeated.

x/15 = 32/40

x = 15×32/40 = 15×4/5 = 3×4 = 12

as you see we get of course the same result doing it that way.

Answer:

C

Step-by-step explanation:

Convert the equation into slope intercept form : y=mx+b

2y=x+4

y=1/2x + 2

The m is the slope and the b is the y intercept

In this equation, the slope is 1/2 and the y intercept is 2

The only graph with y intercept 2 is C

Answer:

1. 3-5

2. 5-3

3. 3-5

4. 5-3

Step-by-step explanation:

This is simple! Just get rid of the parenthesis for each of the expressions shown.

3 + (-5)

the plus sign is next to the negative which is in the parenthesis. Negative times positive is equal to negative. The expression then becomes

3 - 5

Now do the same for the rest!

For things like 3 and 4, you can just flip it like 3-5 and 5-3 because it will all equal the same :]

Hope this helps !!

-Ketifa

Answer:

Imaginary roots

Step-by-step explanation:

The discriminant of a quadratic in standard form [tex]ax^2+bx+c[/tex] is given by [tex]b^2-4ac[/tex].

Given [tex]7x^2+1=5x[/tex], subtract 5x from both sides so that the quadratic is in standard form:

[tex]7x^2-5x+1=0[/tex]

Now assign variables:

The discriminant is therefore [tex](-5)^2-4(7)(1)=25-28=\textbf{-3}[/tex].

What does this tell us about the roots?

Recall that the discriminant is what is under the radical in the quadratic formula. The quadratic formula is used to find the solutions of a quadratic. Therefore, the solutions of this quadratic would be equal to [tex]\frac{-b\pm \sqrt{-3}}{2a}[/tex] for some [tex]b[/tex] and [tex]a[/tex]. Since the number under the radical is negative, there are no real roots to the quadratic (whenever the discriminant is negative, the are zero real solutions to the quadratic). Therefore, the quadratic has imaginary roots.

Answer:

TU = 27

Step-by-step explanation:

We are given two secant segments that are drawn from a circle to meet at an exterior point of the circle. Thus, according to the secant secant theorem, the product of the measure of one secant segment and its external secant segment equals that of the product of the other and its external secant segment.

Thus:

VU*TU = VW*BW

Substitute

7(x + 4) = 9(-2 + x)

7x + 28 = -18 + 9x

Collect like terms

7x - 9x = -18 - 28

-2x = -46

Divide both sides by -2

x = -46/-2

x = 23

✔️TU = x + 4

Plug in the value of x

TU = 23 + 4

TU = 27

Answer:

[tex]S_n = \frac{1 (1 - 3^{10})}{1 - 3} = 29524[/tex]

Step-by-step explanation:

There's a handy formula we can use to find the sum of a geometric sequence, and here it is

[tex]S_n = \frac{a_1 (1 - r^n)}{1 - r}[/tex]

The value n represents the amount of terms you want to sum in the sequence. The variable r is known as the common ratio, and a is just some constant. Let's find those values.

First lets visualize this sequence

[tex]n_1 = 1\\n_2 = 1 + 3\\n_3 = 1 + 3 + 3^2\\n_4=1+3+3^2+3^3\\...[/tex]

Okay so there's clearly a pattern here, let's write it a bit more concisely. For each n, starting at 1, we raise 3 to the (n-1) power, add it to what we had for the previous term.

[tex]S_n = \sum{3^{n-1}} = 3^{1 - 1} + 3^{2 - 1} + 3^{3-1} ...[/tex]

Our coefficients of r, and a, are already here! As you can see below, r is just 3, and a is just 1.

[tex]S_n = \sum{a*r^{n-1}}[/tex]

To finish up lets plug these coefficients in and get our sum after 10 terms.

[tex]S_n = \frac{1 (1 - 3^{10})}{1 - 3} = 29524[/tex]

Answer:

we know that all Lenght of circle is 2πr so 2*π*7=14π

Step-by-step explanation:

14π equal to 360°

but we need just 135° so we should write it kind of radian(π)

if 14π=360°

x=135°

14π*135=360°*x 14π*27=72*x ........= 14π*3=8*x

7π*3=4*x ....... X=21π/4

The length of the arc is 21/π4 in

An answer is an option A. 21/π4 in

The arc period of a circle can be calculated with the radius and relevant perspective using the arc period method.

⇒angle= arc/radius

 ⇒  135°=arc/7

⇒ arc =135°*7

  ⇒arc=135°*π/180° *7in

⇒arc = 21/π4 in

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9514 1404 393

Answer:

  (d)  4.2×10^15

Step-by-step explanation:

Your calculator will tell you the quotient is about ...

  4.21348...×10^15

The least precise number in the division is 1.5, which has 2 significant digits. Therefore, the result should be rounded to 2 significant digits:

  4.2×10^15

Answer:

5/8 ft^2

Step-by-step explanation:

The area of a rectangle is given by

A = l*w  where l is the length and w is the width

A = 5/6 * 3/4

A = 3/6 * 5/4

A = 1/2 * 5/4

A = 5/8 ft^2

Step-by-step explanation:

Fractions represent equal parts of a whole or a collection. 

Fraction of a whole: When we divide a whole into equal parts, each part is a fraction of the whole. 

a fraction has 2 parts

The number on the top of the line is called the numerator. It tells how many equal parts of the whole or collection are taken.  The number below the line is called the denominator.  It shows the total divisible number of equal parts the whole into or the total number of equal parts which are there in a collection. 

There are different types of fraction

Answer:

2x-1 = 5x-14

Step-by-step explanation:

5(2x−1) = 5(5x−14)

Divide each side by 5

5/5(2x−1) = 5/5(5x−14)

2x-1 = 5x-14

Answer:

A.

Step-by-step explanation:

5(2x−1) = 5(5x−14)

10x - 5 = 25x - 70

65 = 15x

x = 13/3.

Take Option A.

2x - 1 = 5x - 14

3x = 13

x = 13/3 so its this one.

B: 10x - 5 = 5x - 14

5x = -9

x = -9/5 so NOT B.

C. simplifies to x = 3. so NOT C.

Answer:

The correct answer is - $720 or 20%.

Step-by-step explanation:

Given:

Total expense = 3600

Electric=30%

Heating and gas=50%

Water and sewer=X%

Solution:

For electric: 3600*30/100 = 1080

for heating and gas: 3600*50/100 = 1800

Left money for expense of water and shower = total - (electric and heating)

= 3600-1880

= 720

Percentage of water and shower = 720*100/3600

= 20%

Answer:

Correct!

Step-by-step explanation:

Thank you this is correct :) I took the test

Answer:

2,7

Step-by-step explanation:

Answer:

(-1,-2)

Step-by-step explanation:

(6 x -1) -(-2 x 5) = 4

-6 + 10 = 4

Answer:

Categorical or Continuous.

Step-by-step explanation:

Because the red appears in each colours (continuous)

9514 1404 393

Answer:

  210 minutes

Step-by-step explanation:

Jason's rate of peeling is ...

  (15 potatoes)/(25 minutes) = 15/25 potatoes/minute = 3/5 potatoes/minute

Janette's rate of peeing potatoes is ...

  (8 potatoes)/(6 minutes) = 4/3 potatoes/minute

Their combined rate is ...

  (3/5 +4/3) = (9 +20)/15 = 29/15 . . . . potatotes/minute

Then the time required for 406 potatoes is ...

  (406 potatoes)/(29/15 potatoes/minute) = (406×15/29) minutes

  = 210 minutes

Answer:

It is (x - 3)³ - 9x(3 - x)

Step-by-step explanation:

Express 27 in terms of cubes, 27 = 3³:

[tex] = {x}^{3} - {3}^{3} [/tex]

From trinomial expansion:

[tex] {(x - y)}^{3} = (x - y)(x - y)(x - y) \\ [/tex]

open first two brackets to get a quadratic equation:

[tex] {(x - y)}^{3} = ( {x}^{2} - 2xy + {y}^{2} )(x - y)[/tex]

expand further:

[tex] {(x - y)}^{3} = {x}^{3} - y {x}^{2} - 2y {x}^{2} + 2x {y}^{2} + x {y}^{2} - {y}^{3} \\ {(x - y)}^{3} = {x}^{3} - {y}^{3} + 3x {y}^{2} - 3y {x}^{2} \\ {(x - y)}^{3} = {x}^{3} - {y}^{3} + 3xy(y - x) \\ \\ { \boxed{( {x}^{3} - {y}^{3} ) = {(x - y)}^{3} - 3xy(y - x)}}[/tex]

take y to be 3, then substitute:

[tex]( {x}^{3} - 3^3) = {(x - 3)}^{3} - 9x(3 - x)[/tex]

Answer:

1. 1.66in

2. 6.66in

3. 3.33in

4. 1inch

Step-by-step explanation:

the area of a rectangle is found by multiplying the length times width or the two sides.

5 x 1/3 is about 1.66 inches

5 x 4/3 is about 6.66 inches

5/2 x 4/3 is about 3.33 inches

and 7/6 x 6/7 is 1 inch

Answer:

other two angle will be

82

as 82+82+16 = 180'

[tex] {a}^{m} \times {b}^{m} = ( {ab)}^{m} [/tex]

please mark this answer as brainlist

Answer:

The point estimate of the proportion of the population that would provide Yes responses is 0.28.

Step-by-step explanation:

Point estimate of the proportion of the population that would provide Yes

The sample proportion of yes responses.

In the sample:

112 yes responses in the sample of 400, so:

[tex]p = \frac{112}{400} = 0.28[/tex]

The point estimate of the proportion of the population that would provide Yes responses is 0.28.