An urn contains three red balls and four blue balls. Draw two balls at random from the urn, without replacement. Compute the expected number of red balls in your sample. (Round your answer to four decimal places.)

Answers

Answer 1

Step-by-step explanation:

in total we have 3+4 = 7 balls.

when we draw the first ball, the probability to draw a red ball is 3/7, and a blue ball 4/7.

when we draw the second ball, we have now only 6 balls in total.

the probabilty to draw a red back now depends also on the result of the first draw.

if the first ball was already red, then we have only a chance now of 2 out of 6.

if the first ball was blue, then we have now a chance of 3 out of 6.

so, the probably to draw at least 1 red ball in 2 draws is the probability of drawing one on the first draw plus the probability of drawing one on the second :

1 - probability to see 2 blue balls

1 - 4/7 × 3/6 = 1 - 12/42 = 30/42 = 0.714285714...

the expected number of red balls in 2 draws is

1 red in first red in first red in second

but not second and second but not first

1×(3/7 × 4/6) + 2×(3/7 × 2/6) + 1×(4/7 × 3/6) = 12/42 + 12/42 + 12/42 = 36/42 = 6/7 = 0.857142857 ≈ 0.8571


Related Questions

Choose the symbol that correctly compares the fractions below.

Answers

Answer:

[tex] \frac{2}{5} > \frac{1}{6} [/tex]

Answer: B. >

#CarryOnLearning

Given the function f(x)=X^2- 3x, find f(-4)

Answers

put -4 in place of x
-4 to the second power is 16 so it would be 16-(-12)= 28

The sum of 8 and a number is 9

Answers

Answer:

The sum of 8 and 1 is 9.

lol

Step-by-step explanation:

From a hot-air balloon, Guadalupe measures a 31^{\circ} ∘ angle of depression to a landmark that’s 316 feet away, measuring horizontally. What’s the balloon’s vertical distance above the ground?

Answers

Check the picture below.

help me plzzzzzzzzzzzzz (NO LINKS)

Answers

Answer:

5^4

Step-by-step explanation:

The rule when you divide two values with the same base is to subtract the exponents.

Cube A has an edge length of 3 inches. Cube B has an edge length double that of Cube A.

What is the volume, in cubic inches, of Cube B?

A. 27in^3

B. 36in^3

C. 216in^3

D. 729in^3

Answers

Answer:

216

Step-by-step explanation:

Cube A volume

3*3*3=27

Cube B volume

6*6*6=216

Edge length of cube B=2(3)=6in

Volume:-

[tex]\\ \sf\longmapsto V=(6)^3[/tex]

[tex]\\ \sf\longmapsto V=6(6)(6)[/tex]

[tex]\\ \sf\longmapsto V=216in^3[/tex]

can y’all please help me

Answers

Answer:

15. d(1,3) e(4,4) g(1,-1) f(4,-2)

16. e(2,-1) f(4,-1) g(2,-3) h(4,-5)

Step-by-step explanation:

These are the coordinates to each point (x,y)

I hope this helps!!

please help!!! i dont understand

Answers

Answer:

C(t)=0.10t + 25

Step-by-step explanation:

gradient = change in y/ change in x = 5/50 = 0.10

the y intercept is 25

so the equation is y = 0.1t + 25

A regular 10-sided polygon has a perimeter of 540 feet. What is
the length of one side?
A.540 feet
B.360 feet
C.270 feet
D.54 feet

Answers

Answer:

  D.  54 feet

Step-by-step explanation:

One side will be 1/10 of the total length of all 10 sides.

  (1/10)(540 ft) = 54 feet . . . length of one side

A line includes the points (-7, 1) and (7, -1). What is its equation in slope-intercept form?
Write your answer using integers, proper fractions, and improper fractions in simplest form.

Answers

Answer:

y=-1/7x

Step-by-step explanation:

m=(y2-y1)/(x2-x1)

m=(-1-1)/(7-(-7))

m=-2/(7+7)

m=-2/14

simplify

m=-1/7

--------------------

y-y1=m(x-x1)

y-1=-1/7(x-(-7))

y-1=-1/7(x+7)

y=-1/7x-7/7+1

y=-1/7x-1+1

y=-1/7x

if v = 6i + 3j, what is ||-10v||

Answers

The values of ||-10v|| is 51.96 units

Complex numbers are square roots of negative numbers. They are expressions that consist of both the real and imaginary axis.

The general form of a complex number is expressed as z = x + iy

Given the complex number v = 6i + 3j,

10v is expressed as 10(6i + 3j)

10(6i + 3j) = 60i + 30j

Take the modulus of the complex number:

[tex]|10v|=\sqrt{60^2+30^2}\\|10v|= \sqrt{1800+900}\\|10v|= \sqrt{2700} \\|10v|=51.96units[/tex]

Hence the values of ||-10v|| is 51.96 units

Learn more on the complex numbers here: https://brainly.com/question/10662770

Which best describes the solution(s) to the equation 5x - 6 - x - 2x + 2?
There is one solution at x =
1
4
O There is one solution at x = 4.
O There is no solution.
There are infinitely many solutions.

Answers

The equation had only one solution and the solution to the given equation is 1

Equations are expressions separated by an equality sign

Given the equation expressed as;

5x - 6 = -x - 2x + 2

Collect the like terms:

5x + x + 2x = 2 + 6

Simplifying the result;

8x =8

Divide both sides of the equation by 8 to have:

8x/8 = 8/8

x = 1

Hence the solution to the given equation is 1

learn more about equation here: https://brainly.com/question/25678139

Darla scored 18 points in her last basketball game, shooting only 2- and 3-point shots. If she made 7 total

Answers

Answer:

3 2-pt shots, 4 3-pt shots

Step-by-step explanation:

2x + 3y = 18

x + y = 7, so x = 7 - y

Substitute in for x

2(7 - y) + 3y = 18

14 - 2y + 3y = 18

14 + y = 18

y = 4

Now put 4 in for y to solve for x

2x + 3(4) = 18

2x + 12 = 18

2x = 6

x = 3

USE THE DIATRIBUTIVE PROPERTY TO WRITE 6(W=5) AS AN EQUIVALENT EXPRESSION

Answers

answer ?

30 or 30W

Step-by-step explanation:

this isn't a real equation. you can't have an equal sign inside a parentheses but assuming that the question is 6(W) and W equals 5, we can substitute the 5 and distribute the 6 to get 6x5 = 30

can someone please help me with this and the first to answer will get marked as brainiest also i need the work to be shown cause i know the answer but just not the work cause i’m confused pls help

Answers

Answer:

x = 3

Step-by-step explanation:

a triangle has 180 degrees in all

a square for an angle is 90 degrees

we can add them all together and get 180

90 + 45 + 8x + 21 = 180

combine like terms

156 + 8x = 180

subtract 156 to each side

8x = 24

then find x

x = 3

Answer:

x=3

Step-by-step explanation:

So the sum of angles of triangle is always 180 degrees.

We already have 45 and 90 but 8x+21 is unknown.

We can solve this by making an equation which is

45 + 90 + (8x+21) = 180.

If we solve this it will be

8x+21+135=180

8x+156 (-156) =180 (-156)

8x (/8) = 24 (/8)

x=3

3x2 - 4x – 7


factor

Answers

Answer:

3x2 = 6

6-4x-7

(6-4x) - 7

2x - 7 = messi ok no xd

3.5-

Step-by-step explanation:

Answer:

[tex](3x-7)(x+1)[/tex]

Step-by-step explanation:

Use the slide-and-divide method:

[tex]3x^2-4x-7[/tex]

[tex]x^2-4x-21[/tex] <-- Multiply last term by the leading coefficient 3

[tex](x-7)(x+3)[/tex] <-- Factor

[tex](3x-7)(x+1)[/tex]

Luis wants to but a skateboard that usually sell for $79.64. All merchandise is discounted by 12%

Answers

Answer:

$79.64

Step-by-step explanation:

I think it's still 79.64

Answer:

it will be equal 70.08 $

What is the quotient of the following division problem?
71= 2 = ?
O A. 37 11
B. 35r1
O C. 35r2
O D. 34 r1

Answers

Answer:

35 remainder 1

Step-by-step explanation:

71 ÷ 2 = 35.5

The 35 is the whole number part of your answer. The .5 part of the answer is .5 of 2, which is 1

OR you can think that

35 × 2 =70. The 1 is the remaining part from 71.

16 #5) Describe the error in finding the value of x. ​

Answers

They forgot 90. Add 90 to the equation to make it correct.

The number of potholes in any given 1 mile stretch of freeway pavement in Pennsylvania has a bell-shaped distribution. This distribution has a mean of 47 and a standard deviation of 7. Using the empirical rule, what is the approximate percentage of 1-mile long roadways with potholes numbering between 40 and 68?

Answers

Answer:   83.85%

This value is approximate.

==========================================================

Explanation:

Let's compute the z score for x = 40

z = (x-mu)/sigma

z = (40-47)/7

z = -1

We're exactly one standard deviation below the mean.

Repeat these steps for x = 68

z = (x-mu)/sigma

z = (68-47)/7

z = 3

This score is exactly three standard deviations above the mean.

Now refer to the Empirical Rule chart below. We'll add up the percentages that are between z = -1 and z = 3. This consists of the two pink regions (each 34%), the right blue region (13.5%) and the right green region (2.35%). These percentages are approximate.

34+34+13.5+2.35 = 83.85

Roughly 83.85% of the one-mile roadways have between 40 and 68 potholes.

What's does A equal?​

Answers

Answer:

x = 65

Step-by-step explanation:

2x + 2(2x-15) = 360

2x + 4x - 30 = 360

6x = 390

x = 65

A crew of highway workers paved 1/5 mile in 1/8
hour. If they work at the same rate, how much
will they pave in one hour?

Answers

Answer: 2/5 Step-by-step explanation: The easiest approach is to realize that one hour is 3 times longer than 20 minutes. The longer the time, the more they will pave.  

Need help please ……………………………..

Answers

Answer:

[tex]-2^{-2} = \frac{1}{-2^{2} } = \frac{1}{4} = 0.25[/tex]

[tex]-2^{-1} = \frac{1}{-2 } = -0.5[/tex]

[tex]-2^{0} = 1[/tex]

[tex]-2^{1} = -2[/tex]

[tex]-2^{2} = 4[/tex]

Step-by-step explanation:

Please help with this question !!

Answers

Answer:

c) i^337 is equivalent to the expression i^137

Answer to the question below please.

Answers

Answer:

The choice 3;

[tex]x = 15 \: \: \: \\ y = 17[/tex]

Step-by-step explanation:

[tex]m < 2 = m < 4[/tex]

Opposite;

[tex]7x + 7 = 112 \\ 7x = 112 - 7 \\ 7x = 105 \\ \\ x = \frac{105}{7} \\ \\ x = 15[/tex]

____o__o___

[tex]m < 3 + m < 4 = 180 \\ 4y + 112 = 180 \\ 4y = 180 - 112 \\ 4y = 68 \\ \\ y = \frac{68}{4} \\ \\ y = 17[/tex]

#6) Find the value of x. Be sure to show your work. ​

Answers

The answer is x=70

My work below in the picture

3 + 12 + 48 + 192 + ...
Whats the answer

Answers

the sequence is to take the previous number and multiply by 4, so the sequence is

3 12 48 192 768 3072 12288

add them all up and you get 16383

Answer:

3, 12, 48, 192, 768, 3072, 12288 these are the next seven numbers

Add them all up and you get

= 16383 Answer C

Step-by-step explanation:

[tex]3, 12, 48, 192[/tex]

So from 3 to 12 is multiply by 4

So we have checked that it works for all of them

Rule:

Each term is: Two to the power of the number3/4 times the number squared plus 0 times the number

I hope this has helped :)

**WILL GIVE BRAINLIEST IF ANSWERED RIGHT** (this is not math but i just put it as math)

Choose all the answers that apply.

Which are benefits of cardiovascular exercise?

decreases the resting heart rate
helps the blood vessels dilate more easily
decreases the stroke volume
weakens the muscles surrounding the lungs
makes the lungs able to fill more completely

Answers

Answer:

Makes the lungs able to fill more

Makes the lungs able to fill more completely and decreases the stroke volume

QUESTION 16 PLEASE HELP ME ASAPP

Answers

Answer: changes over time

Step-by-step explanation: it is always decreasing

30 POINTS!!!! SOMEONE PLEASE HELP ME!!!

Answers

Answer:

  60 nickels

Step-by-step explanation:

When a ratio between coins is given, I like to consider the problem in terms of groups of coins. Here, each group would consist of 1 nickel and 0.20 quarters. The value of that group is

  5¢ +0.20×25¢ = 10¢

Then the number of groups is ...

  (total value)/(value of 1 group) = number of groups

  600¢/10¢ = 60

Since each group has 1 nickel, there are 60 nickels.

__

Check

60 nickels + 12 quarters = $3.00 +3.00 = $6.00

_____

Additional comment

If you want to see this with equations and variables, you can do this.

Let n and q represent the numbers of nickels and quarters, respectively. The given relations are ...

  0.05n +0.25q = 6.00

  q = 0.20n

Substituting for q in the first equation gives ...

  0.05n +(0.25)(0.20n) = 6.00

Simplifying gives ...

  0.10n = 6.00

  n = 6.00/0.10 = 60

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