The random variable X is the number of siblings of a student selected at random from a particular secondary school. Its probability distribution is given in the table. Find the standard deviation of the random variable. Round to three decimal places. x 0 1 2 3 4 5 P(X= x) 11 7 3 1 1 1 48 24 16 6 12 24

Answers

Answer 1

Answer:

1.41

Step-by-step explanation:

Given the table :

X : _____0 ___ 1 ____ 2 ____ 3 ____ 4 ____5 P(X= x)_ 11/48_7/24_ 3/16____1/6___ 1/12 __1/24

The standard deviation = √var(x)

The Variance : Var(X) = (Σx²*p(x)) - μ²

μ = E(X) = Σ(X * p(x)) :

Σ(X * p(x)) = (0*(11/48))+(1*(7/24))+(2*(3/16))+(3*(1/6))+(4*(1/12))+(5*(1/24))

μ = 1.70833333

Var(X): [(0^2*(11/48))+(1^2*(7/24))+(2^2*(3/16))+(3^2*(1/6))+(4^2*(1/12))+(5^2*(1/24))] - 1.70833333^2

= 4.9166667 - 2.9184027663889

Std (x) = √1.9982639336111

Std (x) = 1.4135996

Std (x) = 1.41

Answer 2

Answer:

The Standard deviation of the random variable is 1.414.

Step-by-step explanation:

We Know,

Standard deviation= [tex]\sqrt{variance}[/tex]

Variance is given by:

[tex]Var(X)=E(X^{2} )-E(X)^{2}\\[/tex]

Given,

[tex]x = 0\ 1\ 2\ 3\ 4\ 5\\P(X=x)= \frac{11}{48} \ \frac{7}{24} \ \frac{3}{16}\ \frac{1}{6}\ \frac{1}{12}\ \frac{1}{24} \\[/tex]

[tex]E(X)=[/tex]∑ [tex]x*P(X)[/tex]

[tex]E(X) = 0+ 1*\frac{7}{24} + 2*\frac{3}{16} + 3*\frac{1}{6} + 4*\frac{1}{12} + 5*\frac{1}{24}\\= 1.7083[/tex]

[tex]E(X^{2} ) =[/tex][tex]0+ 1^{2} *\frac{7}{24} + 2^{2} *\frac{3}{16} + 3^{2} *\frac{1}{6} + 4^{2} *\frac{1}{12} + 5^{2} *\frac{1}{24}[/tex]

[tex]= 4.9167[/tex]

So,

[tex]Var(X)= 4.9167- 1.7083^{2}[/tex]

[tex]= 1.99841\\\\Hence, Standard Deviation= \sqrt{1.99841} \\\\ Standard Deviation= 1.413( (upto 3 decimals)[/tex]

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Related Questions

Alice is saving her chore money in a bank account. She makes a deposit of $13 in the first month.
Then every month, she deposits $25. Alice forms a sequence of her account balance, An where n
refers to the number of months. Which of the statements are correct about this sequence?
Select all that apply.

Answers

Answer:

Option (3) and Option (5)

Step-by-step explanation:

Alice invested $13 in the first month.

Then she deposits $25 every month.

Therefore, sequence formed by the deposit will be an arithmetic sequence.

First term of the sequence will be,

[tex]A_1=13[/tex]

Since, recursive formula formula of a sequence is given by the formula,

[tex]A_n=A_{(n-1)}+d[/tex]

Where 'd' = common difference in each term of the sequence

Recursive formula for the sequence will be,

[tex]A_n=A{(n-1)}+25[/tex]

Since, explicit formula for the arithmetic sequence is represented by the formula,

[tex]A_n=A_1+(n-1)d[/tex]

where n = number of term

d = common difference

Therefore, nth term of the sequence formed will be represented by the explicit formula,

[tex]A_n=13+(n-1)25[/tex]

[tex]A_{10}=13+(10-1)25[/tex]

      = 13 + 225

      = 238

[tex]A_{8}=13+(8-1)25[/tex]

     = 188

[tex]A_{12}=13+(12-1)25[/tex]

      = 288

Therefore, Option (3) and Option (5) will be the answer.

Write a minimum 100-word essay on how you can currently use and may use your knowledge and skills of rotations and it's use in digital technology. (WILL MARK BRAINLIEST!! NO SILLY ANSWERS PLS)

Answers

Did you really think someone would write you a whole essay just for fun

How many solutions does this system have?
-x + 2y = 16
4x - 8y = -64​

Answers

Infinite number of solutions
Multiply first equation by -4
You would get the same equation as the second one

Is 16/60 and 4/15 equivalent ratio

Answers

Answer:

Yes

Step-by-step explanation:

4          x   4    =16

____                _____

15         x   4   = 60

Which of the following best describes a change in human society because of the Neolithic Revolution? A. Before the Neolithic Revolution, people lived in organized societies; after the Neolithic Revolution people had to migrate from place to place. B. Before the Neolithic Revolution, people developed complex social hierarchies; after the Neolithic Revolution, people had more social equality. C. Before the Neolithic Revolution, people had developed many specialized jobs in society; after the Neolithic Revolution, people shared the jobs of hunting and gathering food. D. Before the Neolithic Revolution, people obtained food by hunting and gathering; after the Neolithic Revolution, people domesticated plants and animals.

Answers

Answer:A

Step-by-step explanation:

In the Neolithic Revolution, people formed civilizations.

Susan, Mariana y Emma cumplen años el mismo día. Al momento de partir la torta a Valentina le tocó 1/6 , a Camila 2/6 y a Emma 2/6 partes de la…

Answers

It would be la torta

Write the equation of the line fully simplified slope-intercept form.

Answers

Answer:

If your talking about the slope-intercept form, its y = -1/2x + 1

Step-by-step explanation:

Last month, Curtis bought a new mountain bike for $250. In a store advertisement, the mountain bike is on sale for $210. What is the percent of the decrease in the value of the mountain bike?

Answers

Answer:

16%

Step-by-step explanation:

say the percent decrease = x. Then

x/100 x 250 = 210.

x/2 x 5 = 210

x/2 = 210/5

x/2 = 42

x = 42 x 2

x = 84.....

BUT this is not the answer. We need 100-84=16 for the answer.

So the bike dropped 16%. Thank me later :)

If Curtis bought a new mountain bike for $250. In a store advertisement, the mountain bike is on sale for $210. Then 16%  of the decrease in the value of the mountain bike

What is Percentage?

percentage, a relative value indicating hundredth parts of any quantity

Given,

Curtis bought a new mountain bike for $250.

the mountain bike is on sale for $210.

We need to find the percent of the decrease in the value of the mountain bike.

Let the  percent decrease be x.

x/100 x 250 = 210.

5x/2= 210

Divide both sides by five

x/2 = 210/5

x by two equal to two ten by 5, we get x by two equal to forty two

x/2 = 42

Apply cross multiplication

x = 42 x 2

x = 84.

We need 100-84=16.

Hence 16  percent of the decrease in the value of the mountain bike

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Mr.Clark takes 25 minutes to brush his teeth. Mrs. Clark spends
20% longer brushing her teeth. In total, how much time does Mrs.Clark spend brushing her teeth ?
Clark spend brushing her teet

Answers

Answer:

30

Step-by-step explanation:

25 times 1.2= 30

Answer:

30

 Step-by-step explanation:

What is the rectangular form of 12(cos(Pi) + isin(Pi))?

12
-12
12 + i
–12 + i

Answers

The rectangular form of the polar expression [tex]12(cos\pi+ isin\pi)[/tex] is -12

The given equation is:

[tex]12(cos\pi+ isin\pi)[/tex]

The above equation is in polar form

Note that:

[tex]cos \pi = -1\\\\sin\pi = 0[/tex]

Substituting [tex]cos \pi = -1[/tex] and [tex]sin \pi = 0[/tex] into the expression [tex]12(cos\pi+ isin\pi)[/tex] in order to get the rectangular form of the expression

[tex]12(cos\pi+ isin\pi)[/tex]

=  12(-1   +   1(0))

=  12 ( -1  +  0)

=  12(-1)

=  -12

Therefore, the rectangular form of the polar expression [tex]12(cos\pi+ isin\pi)[/tex] is -12

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5 people working for 6 hours per day they complete they task task in 16 days. How many days would it take 8 people if they working 4 hours per day at the same rate?

Answers

Answer:

Can complete a work in 12 days working 8 hours a day Q can complete the same work in 8 days working 10 hours a day if both p and q work together working 8 hours a day in how many days?

Step-by-step explanation:

Answer:

6 hours x 5 person sx 16 days = 480 hours to complete the work.

480/ ( 8person * 4hours) = 15days

Thank you and please rate me as brainliest as it will help me to level up

what is 8 divided by 8 with a multitude of 53 degree angles

Answers

Answer:

1

Step-by-step explanation:

A plane travels 264 miles in 1.1 hours against the wind. On the return trip, it travels the same 264 miles in 1
hour. Find the speed of the wind.

Answers

Answer:

The speed of the wind is 12 miles per hour.

Step-by-step explanation:

Given that the plane travels 264 miles in 1.1 hours with a headwind, the following calculation must be performed to determine its speed:

264 / 1.1 = X

240 = X

Thus, the speed of the plane into the headwind was 240 miles per hour. Now, on the return, with the wind in favor, the route is completed in exactly 1 hour.

Therefore the wind exerts a difference of 24 miles per hour between one trip and another, with which, if it remains stable, its speed is 12 miles per hour (24 / 2).

Harlee uses a device to convert her electronic textbook into braille. Unfortunately, the textbook did not include text descriptions of the diagrams, and 2/3 of the pages have diagrams. Let N be the number of pages Harlee reads to reach the first page with a diagram. Assume that the probability of each page having a diagram is independent. Find the mean and standard deviation of N. Round your answers to one decimal place.

Answers

Answer:

Mean: 1.5

Standard Deviation: 0.9

Step-by-step explanation:

2/3 of the pages have diagrams, and N is the number of pages Harlee reads to reach a page with a diagram. In order to find the mean, divide 1/(2/3) to get 1.5 as your mean, and then divide sqrt(1-(2/3))/2/3 to get .8660, which rounds to .9.

if you share 2 bars in the ratio 1: and 1:7 how mAny pieces will each person get​

Answers

Answer:

I think it will be 4:7 im not very sure tho

Step-by-step explanation:

6 x41=?????????????????

Answers

Answer:

the answer is 246

hope this helps

Plz answer this i have a test and im lost i will give brainliest

Answers

Answer:

its b :) im pretty sure

Step-by-step explanation:

At a carnival, Tammy bought 9 packs of 17 tickets each. She has used 36 of the tickets so far. How many tickets does she have left?

㏒㏑⊂·_·⊃㏒㏑

Answers

117 tickets
You multiply the packs of tickets times the number of tickets per pack which will tell you how many tickets she has in total, 9*17=153 then subtract how many tickets she used from the total number of tickets. 153-36 then you will your answer

True or false: The mapping notation for reflecting point (x,y) about the x-axis is (−x,y).(1 point) This statement is true. This statement is false. The mapping notation for reflecting point (x,y) about the x-axis is (x,−y). This statement is false. The mapping notation for reflecting point (x,y) about the x-axis is (y,x). This statement is false. The mapping notation for reflecting point (x,y) about the x-axis is (−x,−y).

Answers

Answer:

This statement is false. The mapping notation for reflecting point (x,y) about the x-axis is (x,-y)

Step-by-step explanation:

Answer:

false

Step-by-step explanation:

Greta mails 4 postcards on Monday, Wednesday, and Friday. She mails 5 postcards on Tuesday and Thursday and no postcards Saturday or Sunday. She believes that she will mail over 200 postcards if she does this for the entire 12 weeks that she is studying abroad.

Which are reasonable estimates for the number of postcards that Greta mails? Check all that apply.

60
120
200
220
240

Answers

200, 220, and 240. I think, sorry if I’m wrong <33

You are competing in a race. The table shows the times from last year's race. You want your time to be last year's median time with an absolute deviation of at most 4 minutes. Complete the inequality to represent the time (in minutes) you hope to achieve.

Answers

Answer:28 ≤ x ≤40

Step-by-step explanation:Arrange the data from the smallest to the largest

26, 27, 28,32, 32, 33, 35, 36, 38, 40,42,48

Identify the median value

26, 27, 28,32, 32, 33, 35, 36, 38, 40,42,48

Getting the median

(33+35)/2 = 68/2 = 34 minutes

You want your time to be last year's median time with an absolute deviation of at most 6 minutes

This mean ±6 minutes, hence this will be 34 ± 6

34+6=40 and 34-6=28

The inequality will be 28 ≤ x ≤40

Which statement describes the solution to the system of equations?

28

| 2n+Bk = 6

|-5-20%=-15

O The system has exactly one solution.

O The system has exactly two solutions.

The system has no solutions.

The system has infinitely many solutions.

Answers

Answer:

The system has infinitely many solutions.

Step-by-step explanation:

both equations are the same

It means that we have only one equation

so, it can give many solution s

so,

The system has infinitely many solutions.

HOPE THIS HELPS!

PLEASE MARK BRAINLIEST! :)

To prepare for a bake-off, Kent used 560 grams of flour each day for 2 weeks. How many kilograms did Kent use in those 2 weeks?

Answers

Answer:

7.840

Step-by-step explanation:

560 grams times the number of days

560×14=7840grams

1000grams = 1 kilogram soo

7840g=7.840kg

Which part of this graph shows a nonlinear relationship?
Distance from home
2.
Time

Answers

Since 2 is not in a line
Answer=2

Answer:

thanks

Step-by-step explanation:

Jamel has 2 and 2/5 of string. Jamel needs 1/5 of a foot of string to sew a button to a shirt. What is the greatest amount of buttons he can sew onto the shirt with the rest of the string he has?

Answers

Answer:

it's 12

Step-by-step explanation:

2 and 2/5 divide by 1/5 is 12

Answer:

12

Step-by-step explanation:

I had this question on my test and the correct answer was 12

In △ABC, D∈AB so that AD:DB=1:3. If ACDB=18m2. Find AACD and AABC

Answers

Answer:

I really do not know sorry I just need points

Perform the indicated operation.


(4g²-9) ÷ (2g-3)

A. 2g-3

B. 2g+3

C. 2g+3 R 18​

Answers

Answer:

Solving [tex](4g^2-9) \div (2g-3)[/tex] we get 2g+3

Option B is correct.

Step-by-step explanation:

We need to solve [tex](4g^2-9) \div (2g-3)[/tex]

We know that [tex]a^2-b^2=(a-b)(a+b)[/tex]

So, [tex]4g^2-9[/tex] can be written as [tex](2g)^2-(3)^2[/tex]

So, using above formula we will get:

[tex]4g^2-9\\=(2g^2)-(3)^2 \\Using \ formula a^2-b^2 = (a-b)(a+b)\\=(2g-3)(2g+3)[/tex]

So, numerator will become

[tex]\frac{(2g-3)(2g+3)}{(2g-3)} \\Simplifying:\\=2g+3[/tex]

So, solving [tex](4g^2-9) \div (2g-3)[/tex] we get 2g+3

Option B is correct.

Graph: f (x)=−2/3 x−3

Answers

Answer:

-2/3 x-3 graphed will look whit the line going down the negative side (bottom left) of the graph and also passing the (right bottom side of the graph) the points will be  (0,-3)

Step-by-step explanation:

What kind of function describes this situation?

Answers

Answer: A

Step-by-step explanation:

because she's deducting 10 points every day the slope is constant so it has to be a linear equation

Nicole bought a meal in a town with a 9% sales tax. She tips 20% on the bill, and then adds the sales tax. What is the total cost of the meal if she orders a $15 menu item.

Please submit a paragraph response, following the RACE method, to explain how to find the cost of Nicole’s meal.

Answers

Answer:

The total cost of the meal is $19.35.

Step-by-step explanation:

As Nicole ordered a $ 15 menu, and on that price she paid a tip of 20% and the town in which she bought it had a sales tax of 9%, the total cost of the meal is determined by performing the following calculation:

1- Menu $ 15

2- Tip $ 3 (15 x 0.2)

3- Sales tax $ 1.35 (15 x 0.09)

Thus, adding the three expenses, the total cost of the food for Nicole is $ 19.35 (15 + 3 + 1.35).

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