The chances that a student will get 7 marks out of 10 in first attempt of a certain Quiz while attempting Quiz on BlackBoard LMS is 40%. Suppose that 20 students are selected at random then find a probability that i)Exactly 12 students will get 7 marks out 10 in the Quiz. ii)Fewer than 10 students will get 7 marks out 10 in the Quiz. iii)At least 5 students will get 7 marks out 10 in the Quiz.

Answers

Answer 1

Answer:

i) [tex]P(X=12)=0.0355[/tex]

ii) [tex]P(X<10)=0.7553[/tex]

iii) [tex]P(X\geq 5)=0.9490[/tex]

Step-by-step explanation:

Let's start by defining the random variable ⇒

[tex]X:[/tex] '' Number of students that will get 7 marks out of 10 in first attempt of a certain Quiz while attempting Quiz on BlackBoard LMS ''

[tex]X[/tex] is a discrete random variable.

The probability of a randomly selected student getting 7 marks out of 10 is 0.4

(This is a data from the question).

Now, if we assume independence between the students while they are doing the Quiz and also we assume that this probability remains constant , we can modelate [tex]X[/tex] as a binomial random variable ⇒

[tex]X[/tex] ~ Bi (n,p)

Where ''n'' and ''p'' are the parameters of the variable.

''n'' is the number of students attempting the Quiz and ''p'' is the probability that a student will get 7 marks out of 10 which is 0.4 ⇒

[tex]X[/tex] ~ Bi (20, 0.4)  in the question.

The probability function for [tex]X[/tex] is

[tex]p_{X}(x)=P(X=x)=\left(\begin{array}{c}n&x\end{array}\right)p^{x}(1-p)^{n-x}[/tex]    (I)

Where [tex]\left(\begin{array}{c}n&x\end{array}\right)[/tex] is the combinatorial number define as

[tex]\left(\begin{array}{c}n&x\end{array}\right)=\frac{n!}{x!(n-x)!}[/tex]

Replacing the parameters in the equation (I) ⇒

[tex]P(X=x)=\left(\begin{array}{c}20&x\end{array}\right)(0.4)^{x}(0.6)^{20-x}[/tex]    (II)

For i) we need to find [tex]P(X=12)[/tex]

Then, we only need to replace by [tex]x=12[/tex] in equation (II) ⇒

[tex]P(X=12)=\left(\begin{array}{c}20&12\end{array}\right)(0.4)^{12}(0.6)^{8}=0.0355[/tex]

For ii) we need to calculate [tex]P(X<10)[/tex]

This probability is equal to ⇒ [tex]P(X<10)=P(X\leq 9)[/tex] and to calculate it we need to sum [tex]P(X=0)+P(X=1)+P(X=2)+P(X=3)+P(X=4)+P(X=5)[/tex]

[tex]+P(X=6)+P(X=7)+P(X=8)+P(X=9)[/tex]

We can do it summing each term or either using any program.

The result is [tex]P(X<10)=P(X\leq 9)=0.7553[/tex]

Finally for iii) we need to find  ⇒ [tex]P(X\geq 5)[/tex]

This probability is equal to ⇒ [tex]P(X\geq 5)=1-P(X\leq 4)[/tex] ⇒

[tex]1-P(X\leq 4)=1-[P(X=0)+P(X=1)+P(X=2)+P(X=3)+P(X=4)][/tex]

Again we can find each term by using the equation (II) or either using a program. The result is [tex]P(X\geq 5)=0.9490[/tex]


Related Questions

Which expression is equivalent to 6(4v)?

Answers

Answer:

24v

Step-by-step explanation:

simply multiply perform the distributive property. so multiply 6 and 4 and you should get 24. after just add in the v.

pls mark brainlest

Hello!!!

Your answer would in fact Be 24 the steps are super simple what may confuse you is the v it is quite confusing but v is basically a variable that signifies multiplication as it is together with the 4 but this here is an expression because it has nothing equal to it so we have no answer to define what the v is! Also a tip is whenever a number has parenthesis and a number is outside of the parentheses without any sign that signifies multiplication :)!! So as of now if your not learning how to find variable answers then you can basically pretend the v is not needed but have a nice day and I really hope this has helped you!! I have spent quite a while typing this so I hope this is all worth it!!

a lawnmower that regularly sells for %150 was discounted by 25% off.

Questions:

Markup?

Sale price?

Answers

To take 25% off, you want to do 1-.25 which equals .75. That means that you have to pay 75% of the cost after the 25% off discount.

Multiply the cost, 150, by .75 to find the new price after the discount.
150x.75=112.5

The price is now $112.50

Hope this helps!

Solve the equation 4x - 6 = 34. Write a justification for each step.


47-6= 34


Given equation


+6 +6


4x


Simplify.


= 40


4x 40


44


[2]


X= 10


Simplify


[1] Addition Property of Equality,


[2] Reflexive Property of Equality


[1] Substitution Property of Equality,


[2] Division Property of Equality


[1] Division Property of Equality,


[2] Subtraction Property of Equality


[1] Addition Property of Equality:


[2] Division Property of Equality


8

Answers

Answer:

[1] Addition property of equality

[2] Division property of equality

Step-by-step explanation:

Given the equation, [tex] 4x - 6 = 34 [/tex], the following are steps and justification for each step taken:

[tex] 4x - 6 = 34 [/tex] => Given equation

Add 6 to both sides

[tex] 4x - 6 + 6 = 34 + 6 [/tex] => addition property of equality [1]

[tex] 4x = 40 [/tex] => simplify

Divide both sides by 4

[tex] \frac{4x}{4} = \frac{40}{4} [/tex] => Division property of equality [2]

[tex] x = 10 [/tex] => simplify

The justification for the steps taken are:

[1] Addition property of equality

[2] Division property of equality

PLSS HELPPP HELP ASP

Answers

Answer is D.
Answer is D.
The answer for this question is D

in the expression shown below, the number 2 and 5 that are place in front of the variables are called
2x^2+5x-3

A. Degrees
B. Polynomials
C. Coefficient
D. Radicals ​

Answers

Coefficient because the number in front of the variable is the coefficient

At a plant nursery, 5/8 of the planets for sale are flowers and another 1/3 of the plants are shrubs. What amount of the plants for sale are either flowers or shrubs?

Answers

Answer: 23 / 24

Step-by-step explanation:

Given that:

Fraction of flowers for sale = 5/8

Fraction of shrubs for sales = 1/3

Amount of flowers that are either flowers or shrubs :

(Fraction of flowers +. Fraction of shrubs)

(5/ 8 + 1 /3)

L.C.M of 8 and 3 = 24

= (15 + 8) / 24

= 23 / 24


Karen has 560 friends and family on social media of the friends, 50% are from high school, and 30% are from her after school job. The rest are family
members
How many family members does Karen know on social media?

Answers

Answer: 112

Step-by-step explanation:

560/5

Please help need this before 4:15pm
In which part of the periodic table (top-left, top-middle, top-right, bottom-left, bottom-middle, bottom-right, middle-left, middle-center, middle-right) do we find most of the atoms that make up life?

Answers

Answer:

Top right i believe

Step-by-step explanation: the elements that make up life are carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

17) When filled to maximum capacity, a silo can hold about 4,000 cubic meters of corn. The radius of the silo is 8 meters. To the nearest meter, what is the approximate height (h) of the silo? ​

Answers

Answer: ion know i'm guessing 4

Step-by-step explanation: because it shows 8 at the top, so since it's full and it's 4,000 then that'll basically make 8 the 4000, so since 4 is half of 8 then we prolly have our answer right there

Answer: It would be 20

Step-by-step explanation: The formula for height would be h= v/pi r squared, just plug in the numbers

the square root of 84 is it closer to 9 or 10

Answers

Answer: It is closer to 9

Step-by-step explanation: The square root of 84 is 9.16515139

Answer:

9

Step-by-step explanation:

The square root of 84 rounded the hundredth is 9.17, making it closer to 9 than 10.

6x(2x+y-5) rewrite as a sum

Answers

Answer:     12x^2+6xy−30x

^=power sighn

Step-by-step explanation:

6x(2x+y−5)=(6x)(2x+y+−5)=(6x)(2x)+(6x)(y)+(6x)(−5)=12x^2+6xy−30x

Help pls<---
ASAP DUE TODAY BY 9:05

Answers

Answer:covert - 2/3 to -4/6. Then after you do the math...you get -9/6....simplify that to -3/2e=-27. You then multiply -27 by the reciprocal -2/3 and the answer is 18.

Step-by-step explanation:

Rounding decimals. 0.01426; thousandths

Answers

Answer:

0.014

Step-by-step explanation:

What is the solution to the equation?
3 + 3x – 5 = r
A.
-2 and -7
B.
2 and 7
O c.
-2
D. 7

Answers

Answer: -2 and -7 i think
A -2 and -7 is the answer

A survey was conducted to see how many people ride a bus to school everyday 160 people reported that they ride the bus school everyday this number represents 80%of the people surveyed how many were surveyed

Answers

Answer:

200 people

Step-by-step explanation:

A teacher weighed 145 lbs in 1986 and weighs 190 lbs in 2007. What is the rate of change in weight? HELP

Answers

Answer:

c

Step-by-step explanation:

she gained 45 pounds which is 15/7 of 145

The answer is 15/7 and here’s the explanation :)


The point 3/4 of the way from A(-4,- 7) to B(12, 5)

Answers

Answer:

The coordinates of C are (8,2)

Step-by-step explanation:

We are given the segment from A(-4,-7) to B(12,5) and it's required to find a point C(x,y) that is located at 3/4 of the distance from A to B.

This means that:

[tex]d_{AC}=3/4\cdot d_{AB}[/tex]

where dAC is the distance from A to C and dAB is the distance from A to B.

The same proportion of the distances is satisfied by the coordinates of the point C, that is:

[tex]\displaystyle x-x_A=\frac{3}{4}(x_B-x_A)[/tex]

Adding xA:

[tex]\displaystyle x=\frac{3}{4}(x_B-x_A)+x_A[/tex]

[tex]\displaystyle x=\frac{3x_B+x_A}{4}[/tex]

Similarily:

[tex]\displaystyle y=\frac{3y_B+y_A}{4}[/tex]

Calculating:

[tex]\displaystyle x=\frac{3(12)-4}{4}[/tex]

x = 8

[tex]\displaystyle y=\frac{3(5)-7}{4}[/tex]

y = 2

The coordinates of C are (8,2)

PLEASE HELP! THANK YOU!!!

Answers

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[tex]3(x - 2) = 12[/tex]

[tex]x = 6[/tex]

_________________________________

[tex]6(x + 5) = 54[/tex]

[tex]x = 4[/tex]

_________________________________

[tex]3x + 5 = 32[/tex]

[tex]x = 9[/tex]

_________________________________

[tex]5(x + 7) = 45[/tex]

[tex]x = 2[/tex]

_________________________________

[tex]7x + 6 = 41[/tex]

[tex]x = 5[/tex]

_________________________________

[tex]2(x + 7) = 29[/tex]

[tex]x = 7.5[/tex]

_________________________________

[tex]4(x + 3) = 30[/tex]

[tex]x = 4.5[/tex]

_________________________________

[tex]5(x - 4) = 20[/tex]

[tex]x = 8[/tex]

_________________________________

[tex]3x - 10 = 23[/tex]

[tex]x = 11[/tex]

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Card A: x = 6

Card B: x = 4

Card C: x = 9

Card D: x = 2

Card E: x = 5

Card F: x = [tex]\frac{15}{2}[/tex]

Card G: x = [tex]\frac{9}{2}[/tex]

Card H: x = 8

Card I: x = 11

There you go bud. :')

You owe me for this lol.

What is the measure of angle y?

Answers

Answer:

y =50°

Step-by-step explanation:

40°+90°+y = 180° {the sum of angle of triangle is 180°}

or, 130°+ y = 180°

or, y = 180°-130°

or, y =50°

The value of the measure of an angle y in a triangle would be 50 degrees.

Used the concept of angle in a triangle that states,

The sum of all three interior angles in a triangle gives 180 degrees.

Given that,

A triangle is shown in the attached figure.

Here, the triangle shown in the image is a right-angle triangle.

Hence, a measure of an angle = 90 degree

And, the second measure of an angle = 40 degree

So, the sum of interior angles in a triangle gives 180 degrees.

Hence,

40° + 90° + y = 180°

Solve for y,

130° + y = 180°

y = 180° - 130°

Therefore, the value of y is,

y = 50 degree

To learn more about the triangle visit;

brainly.com/question/1058720

#SPJ6

Please answer correctly !!!!!!!!!!!!!!!!!!! Will mark brainliest !!!!!!!!!!!!!!!!!!!!

Answers

Answer:

x is also 63 degrees this is because vertical angles are congruent or like equal in measure

Step-by-step explanation:

HOPE THIS HELPEDDDD

Answer:

63 degrees

Step-by-step explanation:

Since m is parallel to n, the angle that is marked 63 degrees and x are alternate interior angles. The alternate interior angle theorem states that alternate interior angles are congruent when a line cuts through two parallel lines. So, since m and n are parallel, these are congruent angles, making x also 63 degrees.

Solve equation Y=9x-70 and y=2x-32

Answers

Step-by-step explanation:

y = 9x - 70 ...1

y = 2x - 32 ...2

...1 - ...2

0 = 7x -38 ...3

7x - 38 = 0

7x = 38

x = 38/7

6 gallons to 42 gallons
Express each ratio as a fraction in the simplest form

Answers

The answer is 1/7. This is in fraction form
If you have school calculator just put it in and you should get 1/7

Triangles ABC and DEF are similar. Find e.

A.) 11
B.) 12
C.) 10
D.) 9

Answers

E is 10. D is 12. So C I guess

PLEASE HELP

At a family reunion, 6 families share 500 photos equally. How many photos does 13 each family get and how many photos are left over?​

Answers

Answer:

83 photos each

2 photos left over

Answer:

Each Family gets 83 photos each and 2 photos are left over

Step-by-step explanation:

Hope this helps and have a great day :)

It takes Taylor hour to make of a batch of cookies. About how long will it take him to make 8 batches?
B.
3.6 hours
C.
5.4 hours
D.
7.2 hours

Answers

Answer:

it would be 8 hours.....

Step-by-step explanation:

      im  am a bit confused, why is that not an answer choice

5. Find the difference of 785 and 543
785+543

Answers

Step-by-step explanation:

785-543=242

difference means subtract

300x7065
A tough one can you solve it without looking the answer up or not cheating in any way

Answers

2,119,500
explanation: you multiply

What is the value of x

Answers

Answer:

x=39

Step-by-step explanation:

First I try to find the angle measurements for the rest of the angles inside the triangle. I saw that the 68 degrees and I notice that it was vertical angles, meaning that the inside is also 68. I then notice that the 107 and the other unknown angle besides x must be 180 when adding up, so I can do 180-107=73. Now I know that that angle is 73 degrees I can find x by solving this equation 180=73+68+x, which the answer comes out to be 39. so x=39.

Hope this helps you

Your friend has $100 when he goes to the fair.he spends $10 to enter the fair and $20 on food.rides at the fair cost $2 per ride.which function can be used to determine how much money he has left over after x rides

Answers

Answer:

The answer is A f(x)=-2x + 70

Step-by-step explanation:

What is the range of the function on the graph?
LO
4
all the real numbers
O all the real numbers greater than or equal to 0
O all the real numbers greater than or equal to 2
O all the real numbers greater than or equal to -3
21
2 1
2 3 4 5 x
-5 -4 -3 -2 -11
-2
-3
-4
-5

Answers

the answer is all real numbers

The range of the function on the graph are all the real number greater than or equal to -3.

What is Function?

A function is a relation from a set A to a set B where the elements in set A only maps to one and only one image in set B. No elements in set A has more than one image in set B.

Given the graph of a function.

A function f(x) has the domain equal to the all values of x that the function is defined for.

Range of the function is the set of all the values of the function for the x in the domain.

Here, the function values are from infinity to -3 and then again mover from -3 to infinity.

So the range consists of all the real numbers from -3.

Hence the range of the function is the set of all real numbers from -3.

Learn more about Range here :

https://brainly.com/question/21027387

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