If 3 balls are drawn at random from a bag containing 3 red and 4 blue balls,
what is the expected number of red balls in the sample?

Answers

Answer 1

Answer:

The expected number of red balls in the sample is 1.2857.

Step-by-step explanation:

The balls are chosen without replacement from the sample, which means that the hypergeometric distribution is used to solve this question.

Hypergeometric distribution:

The probability of x sucesses is given by the following formula:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

In which:

x is the number of sucesses.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

The expected value of the hypergeometric distribution is:

[tex]E(X) = \frac{nk}{N}[/tex]

3 red balls in the sample:

This means that [tex]k = 3[/tex]

3 balls are drawn:

This means that [tex]n = 3[/tex]

Total of 3 + 4 = 7 balls:

This means that [tex]N = 7[/tex]

What is the expected number of red balls in the sample?

[tex]E(X) = \frac{nk}{N} = \frac{3*3}{7} = 1.2857[/tex]

The expected number of red balls in the sample is 1.2857.


Related Questions

questions and answer choices attached to photo, please help ASAP :)

Answers

Answer:

D

Step-by-step explanation:

10 x 10 x 29 x .5 = 1,450

Help is needed please????

Answers

Answer: let F(x)=y

y=2x+5

Step-by-step explanation:

At the U.S. Open Ternis Championship a statistician keeps track of every serve that a player hits during the tournament. The statistician reported that the mean serve speed of a particular player was 97 miles per hour (mph) and the standard deviation of the serve speeds was 13 mph. Assume that the statistician also gave us the information that the distribution of the serve speeds was mound-shaped and symmetric. What proportion of the player's serves was between 110 mph and 136 mph

Answers

Step-by-step explanation:

At the U.S. Open Tennis Championship, a statistician keeps track of every serve that a player hits during the tournament. The statistician reported that the mean serve speed of a particular player was 102 miles per hour (mph) and the standard deviation of the serve speeds was 15 mph.

If you use the amount of flour that was used on Day 4, how many
cups of flour will you use?

Answers

I need a photo to help you can you send me one?

Donna fed of the chickens at a farm. Which decimal is equal to the fraction of 11 chickens Donna fed?
__
A. 0.09
_
B. 0.09
__
C. 0.01
_
D. 0.01​

Answers

either a or b not 0.01

I believe the answer is:
A. 0.09

Identify the distance between the points (9,7,3) and (5,3,2), and identify the midpoint of the segment for which these are the endpoints. Round to the nearest tenth, if necessary.

Answers

Using it's formula, it is found that the distance between the two points is of 5.7 units. Additionally, the midpoint is (7, 5, 2.5).

What is the distance between two points?

Suppose that we have two points, [tex](x_1,y_1)[/tex] and [tex](x_2,y_2)[/tex]. The distance between them is given by:

[tex]D = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

In this problem, the points are (9,7,3) and (5,3,2), hence:

[tex]D = \sqrt{(9 - 5)^2 + (7 - 3)^2 + (3 - 2)^2} = 5.7[/tex]

The distance between the two points is of 5.7 units.

What is the midpoint?

The midpoint is the mean of the coordinates, hence:

xM = (9 + 5)/2 = 7.yM = (7 + 3)/2 = 5.zM = (3 + 2)/2 = 2.5.

The midpoint is (7, 5, 2.5).

More can be learned about the distance between two points at https://brainly.com/question/18345417

if f(x) = 5 + 4( x - 4)^2

then what is f(7)

Answers

Answer:

41

Step-by-step explanation:

f(7) = 5 + 4(7-4)²

= 5 + 4(3²)

= 5 + 4(9)

= 5 + 36

Answer:

f(7)=39

Step-by-step explanation:

f(7)=5+4((7)-4)^2

=5+4(3)^2

=5+4(9)

=5+36

=39

guys please help me, im really having a hard time on those questions and more other questions please!!

Answers

Answer:

1. 21, 22

2.29,30

Step-by-step explanation:

1. m+4>24

subtract both sides by 4

m>20

Two values that are greater than 20 are 21 and 22.

2. 7<x/4

multiply both sides by 4

28<x

Two values that are greater than 28 are 29 and 30.


f(x) = x + 4; find f(-8).
A-12
B -4
C 12
D 4

Answers

Answer:

A. -12

Step-by-step explanation:

When it says, "find f(-*)" it is telling you that that is f(x), so you're now basically solving:

-8=x+4

Which, would have to be -12.

In an isosceles triangle, the base angles measure 65°. Which of the following expressions is a way to calculate the measure of the third angle?​

Answers

Answer:

its A

Step-by-step explanation:

its A ️ ‍♀️ ️ ‍♂️ ️

180-2(65). The base are both 65 and a triangle adds up to 180.

Please help me (NO LINKS)

Answers

Answer:

[tex]0.25( \frac{1}{4} ) \\ 0.50( \frac{2}{4}) \\ 1.25(1 \frac{1}{4} )[/tex]

hope it's what u want

6) WILL MAKE BRAINLIEST

write the slope-interception form of the equation of each line.

Answers

the answer would be C, y=2x-1

Find an
equation for the line through (-6, 3) and
parallel to y = 3x + 1.

Answers

Since this line is parallel to y = 3x + 1 their slopes are equal. The slope is equal to 3. The line is also passing the point (-3,4).

This is the format of the line parallel to y = 3x + 1

y = 3x+ b

This line passes through point (-3, 4)

Replacing the values of y and x coming from the coordinates of (-3, 4)

4 = 3 * (-3) + b

Solving for the y-intercept b

4 = -9 + b

b = 4 + 9

b = 13

Knowing the slope as equal to 3 and the y-intercept as 13 the equation of the line is

y = 3x+13

The Ratio of 5 cows for every 2 dogs is equivalent to what ratio?

A. 20:8
B. 6/12
C. 4 to 10

( If it is right I will mark it as brainiest ong)

Answers

20:8

Step-by-step explanation:

5:2

20:8

5×4= 20 and 2×4= 8

Answer:

A is the right answer. If you multiply the ratio 5: 2 by 4 it will give you 20:8

Guys help me with this quick pls​

Answers

Answer:

[tex]117 = 66 + \beta \\ \beta = 51[/tex]

What is nine divided by two

Answers

Answer: 4.5

Step-by-step explanation:

9/2 = 4.5

have a good day. you have to use division, and plus, 4.5 + 4.5 = 9

a)Solve for x:
y = 130 − 4x

b) What is the value of x when y = 120

Answers

Answer:

[tex]x = \frac{5}{2}[/tex]

Step-by-step explanation:

y = 130 - 4x

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

120 = 130 - 4x

-10 = -4x

x = [tex]\frac{-10}{-4} =\frac{5}{2}[/tex]

8,546.54 to nearest 1,000.00​

Answers

9,000

Step by step: remember 5 or higher raise the score 4 or less let it rest. You underline the thousands place in this situation then look back to the number right to it. Since that number is 5 you must change the 8 to a 9. All the other numbers to the right if 8 is now 0.

pls help me i am very behind and confused

Answers

i thinks it’s a sorry if i am wrong

x > -3 For each statement list three numbers that would make a solution to the inequality true.

Answers

Answer:

x = -2

x = -1

x = 0

Step-by-step explanation:

Find three numbers to the left of -3 on the number line

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

What is the missing length?
6 mi
t
area =
60 mi2

Answers

Answer:

10 mi

Step-by-step explanation:

6mi x t = 60mi^2

this is basically

6 x t = 60

divide 6 to both sides

t = 10

Find the value of the trigonometric ratio.

Answers

Answer:

D

Step-by-step explanation:

sin=opposite/hypotenuse

Sinx=40/41

14. A cone has twice the base diameter and
three-fourths the height of a cylinder. Can
you tell what the relationship between the
volume of the cone and the volume of the
cylinder is? Explain your reasoning.

Answers

Answer:

1+1 is cannot be

Step-by-step explanation:

jajauajhwhahwwhhahwhauwu

Find value of x for both

Answers

Answer:

19??????????????????

Question and Answers below in photo!! Please answer! Will mark BRAINLIEST! ⬇⬇⬇⬇⬇⬇⬇

Please answer ALL questions in order for BRAINLIEST! NO links or else you will be reported and maybe even get banned.

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

Find the volume of the triangular prism:

-27yd^3

-72yd^3

-240yd^3

-360yd^3

Answers

Answer: 72

Step-by-step explanation:

[tex]V=\frac{1}{2}(3)(8)(6)=\boxed{72}[/tex]

You want to know if the students in your school have been to your town’s skate park. You randomly survey 50 of the 1100 students at your school. Of those surveyed, 15 have been to the skate park and 35 have not. You conclude that 30% of the students in your school have been to the skate park. Which statement below best describes your conclusion

Answers

Answer:

Step-by-step explanation:

The conclusion is invalid

Which value (s) of x are solution(s) of the equation below?
A. x = 2, 4
B. x = -1, 4
C. x = 2
D. x = -1

Answers

Answer:g

Step-by-step explanation:

please tell me the answer to 6 % of $ 4,379

Answers

256.74 should be the answer just use a calculator

please help. Will mark brainliest if correct. ( links will be banned)

Answers

Answer:

how many tries do you have?

I think its d because the proportion 6/4 and LM/6 cuz the smaller number is on the bottom? I dont know try it. how many tried do you have?

Its either d or b

For what values of x is the expression below defined?

Answers

Answer:

x > 0

Step-by-step explanation:

Given :-

√[3x²] ÷ √[4x ]

And we need to find the value of x for which the expression is defined . The expression is ,

[tex]:\implies[/tex] [3x²] ÷ [4x]

As we can see that x is inside the squareroot. So for defining the expression the value of x should be Greater than 0 . As negative inside the squareroot will give rise to imaginary numbers.

Solution :-

[tex]:\implies[/tex] x > 0

In interval notation :-

[tex]:\implies\bf x \in ( 0 , \infty) [/tex]

Therefore x should be Greater than 0 .

Other Questions
PLZZZZZ HELPPPPP ASAPPPP!!!!!!!NO PLAGIARISM!!How did the assassination of Franz Ferdinand cause a global war? What sorts of background tensions were brought to a boiling point by that event? 6) When fishing, why should fisherman never exceed the growth rate of the population? if you have 6% guanine how much of the other bases do you have? please hurry difference between manager and management .Mr. and Mrs. De La Paz ate 50% of the pizza. If the pizza had 20 slices, how many slices did each eat help aging lol A camcorder costing 150 has a markup rate of 35% . Find the markup. A data set has a minimum of 7, a maximum of 22, a mean of 13, a first quartile of 10, and a third quartile of 15. What is its IQR? Can someone plz helppp meeeee What is the median of this data set? 18, 16, 22, 14, 17, 19, 15, 19, 2216 171819 HELP ASAP!! no links plsIf a point is randomly picked inside the square, what is theprobability that it will be inside the circle? Round your answer tothe nearest percent. Which of the essential nutrients provide calories for energy?Avitamins A and K, calcium and sodiumBwater, sugar and fatprotein, complex carbohydrates and fattural15 FreDVitamin C and E, Iron and Magnesiumpport essay on MY ABITION OF LIFE Choose All the numbers that round down when rounding to the nearest hundred Divide. Give the exact answer, written as a decimal. 5. If 4 moles of nitrogen gas reacts with excess hydrogen gas, how many moles of NH3 will be produced?Be sure to balance the equation first.__N2 + __ H2 __ NH3a. 8 moles NH3b. 4 moles NH3C. 2 moles NH3d. 12 moles NH3 What was the significance of the Tet Offensive from a military perspective? PLEASE HELP!!! Do some online research on farmers markets in Mexico. Write a paragraph in Spanish describing the purpose and focus of farmers markets. write the formula of mechanical advantage Can someone help me answer this! PLEASE HELP!!!! WILL GIVE BRAINLIEST!!!! I need help writing the question that this scientific investigation is seeking to answer and writing a hypothesis!!!