For a discrete random variable that takes a value of 8 with probability .75 and a value of -4 with probability of .25, what is the expected value and what is the variance

Answers

Answer 1

Answer:

5.20

Step-by-step explanation:

X : ______ 8 ____ - 4

P(X) : ___ 0.75 __ 0.25

The expected mean E(x) :

E(x) = ΣX / n

n = sample size = 2

E(x) = (8*0.75) + (-4*0.25)

E(x) = 6 - 1

E(x) = 5

The standard deviation : sqrt(Var(x))

Var(x) = Σx²p(x) - E(x)²

Var(x) = (8^2 * 0.75) + (-4^2 * 0.25)) - 5^2

Var(x) = ((64 * 0.75) + (16* 0.25)) - 25

Var(x) = (48 + 4) - 25

Var(X) = 27

Standard deviation = sqrt(27)

Standard deviation (x) = 5.1961524

Standard deviation = 5.20


Related Questions

What is 10 divided by 5/8

Answers

Answer:

its 16 lol

Step-by-step explanation:

I just did the math

16

16 is the answer
hope i helped. have a good day

Suppose that the functions q and r are defined as follows.
q(x) = -x-1
r(x) = 2x² – 2
Find the following.
(q*r)(-5) =
(r*q) (-5) =​

Answers

Step-by-step explanation:

r(-5) = 2*25 - 2 = 48

Q(-5) = 5 - 1 = 4

Please answer right brineliest to wover right

Answers

Answer:

10

15

-5

-35

-30

0

Step-by-step explanation:

Step-by-step explanation:

A: 10 degrees

B: 15 degrees

C: -5 degrees

D: -35 degrees

E: -30 degrees

F: 0 degrees

Suppose the heights (in inches) of adult males in the United States are normally distributed with a mean
of 71 inches and a standard deviation of 3 inches.
Find the percent of men who are no more than 65 inches tall.
The percent of men who are 65 inches tall or below is
%.

Answers

iyyjj woo hoo wia then 15%

Which expression shows the result of applying the distributive property of 3(2x – 6)?
(NEED ANSWER QUICK!)

52 - 3
20 – 18
62 - 6
6.2 – 18

Answers

Answer:

6x - 18

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Distributive Property

Step-by-step explanation:

Step 1: Define

3(2x - 6)

Step 2: Expand

Distribute 3:                    3(2x) + 3(-6)Multiply:                          6x - 18

Step-by-step explanation:

[tex] \huge3(2x - 6) = 6x - 18[/tex]

(6x-18) is the right answer.

Help me with this pls!!

Answers

Answer:

5 3/4 hours

Step-by-step explanation:

They drove 3 1/2 hours then  2 1/4 hours. We need to find the total of these to find how long this part of the trip was

(3 + 1/2) + (2 + 1/4) = 5 + 1/2 + 1/4

For 1/2, we can multiply both the numerator and denominator by 2 to get

1/2 = 2/4

Substituting that in, we get

5 + 2/4 + 1/4

= 5 + 3/4 hours

Compute the mean of the following population values:

6, 3, 5, 7, 6.

Answers

Answer:

The mean (average) is 5.4 or 5 if you're rounding.

Step-by-step explanation:

Mean is the average of all of the numbers.

Add them up: 6+3+5+7+6 = 27

Divide 27 by the amount of numbers you have(5): 27/5

Solve: 5.4

The mean of the given values 6, 3, 5, 7, and 6 will be 5.4.

What is mean?

mean is the average of a data set. Mean gives us the idea of that how much amount of overall data have.

Mean = sum of data / Number of data

For example, if you have marks in 5 subjects like 40,45,44,46,48 then the mean will be

( 40 + 45+ 44 + 46 + 48) /5 = 44.6.

Given the data set;

6, 3, 5, 7, 6

Mean = (sum of data) / (number of data)

Mean = (6 + 3 +  5 + 7 + 6)/5

Mean = 27/5

Mean = 5.4

Hence the mean will be 5.4.

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HELP ME FAST PLEASE I NEED THIS VERY SOON!!! you’d be a lifesaver omg

There are 600 seats in the auditorium. This is 112 less than the number of seats in the gymnasium. How many seats are in the gymnasium?



Answers

712 is the answer of this question

The answer would be 712

Explanation:

600

+

112

———

712

if we just passed a sign which says that harrison is 25 miles away and turkey is 40 miles ahead, how far will we have to go to be halfway between turkey and harriso

Answers

Answer:

You will need to go 7.5 miles to be halfway between Harrison and Turkey

Step-by-step explanation:

If you see a sign saying that Harrison is 25 miles away and that Turkey is 40 miles ahead, then the distance from Harrison to Turkey must be 40 miles - 25 miles = 15 miles.

If you drive up to be halfway between Harrison and Turkey, then you need to travel 15/2 = 7.5 miles.

You will need to go 7.5 miles to be halfway between Harrison and Turkey

Expand the following:
a) x(x + 6)
b) x(5x - 1)
c) 3x(6x + 5)
d) 4x(2x – 3y)​

Answers

Answer:

a) x(x + 6)  = x · x + x · 6 = x² + 6x

b) x(5x - 1)  = x · 5x - x · 1 = 5x² - x

c) 3x(6x + 5)  = 3x · 6x + 3x · 5 = 18x² + 15x

d) 4x(2x – 3y)​ = 4x · 2x - 4x · 3y = 8x²-12xy

Round the following numbers to 2 decimal places.
b)
562.6783​

Answers

Answer:

b is the correct answer i know it is

the length of a living room is 12 fert and its width is 10 1/2 feet. the length of the room is being expanded by x feet. select all the expressions that represent the area of the living room in square feet

Answers

Answer:

vbhjnkmlnkbjvhcgfdxgcvhbjnncnng

Step-by-step explanation:

cxvcxbvcbcvbvcbcvbvcvbb

Answer:

thanks

Step-by-step explanation:

I need help please!!!!

Answers

Answer:

A) intersecting, 1 solution

B) Same Line, infinite number of solutions.

Four friends share the profit of a lawn care service equally. The friends charge $45 per lawn and spend $30 of their total earnings on gasoline for the lawnmowers each week. Which inequality can be used to find m, the number of lawns they need to mow next week so that each person earns at least $275? A. 45m - 30/4 _> 275 B. 45m/4 - 30 _>275 C. 45m - 30/4 _< 275 D. 45m/4 - 30 _< 275​

Answers

Answer:

The answer is actually A) 45m-30/4 ≥ 275

Step-by-step explanation:

It says, "of the total earnings", so after they took off the 30 dollars, they split it between themselves. Hope this helps ;)

a - 48 = 18
What is a?

Answers

Answer:

A=66

Step-by-step explanation:

Answer:

a=66

Step-by-step explanation:

You do an inverse operation to find your answer, in this case it is addition, so you add 48 and 18 to get 66!

please help! which expression is equivalent to (-√-1)?
A: i^31
B: i^29
C: i^24
D: i^18

Answers

Answer:

Here Is Your Answer i^31

In ΔIJK, k = 26 cm, ∠I=135° and ∠J=11°. Find the length of i, to the nearest centimeter.

Answers

Answer:

33 cm

Step-by-step explanation:

Given

Triangle IJK with:

Side k = 26 cm, ∠I = 135°, ∠J = 11°To findThe length of side iSolution

Find angle K:

∠K = 180° - (135° + 11°) = 34°

Use the low of sines to findthe value of i:

i/sin I = k/sin Ki = k sin I / sin Ki = 26 * sin 135° / sin 34° = 33 cm (rounded to the whole number)

PLS HELP WILL GIVE BRAINLIEST ANSWER

Answers

Answer:

8

Step-by-step explanation:

2(20-8x)=5x-2

40-16x=5x-2

42=21x

x=2

HK=5x-2 = 5(2)-2 = 10-2 = 8

Mr. George has 5 bookcases in his classroom. Each bookcase has 3 shelves. Each
shelf has 20 books. How many total books are on Mr. George's 5 bookcases?
CLEAR
SUBMIT
300 books
160 books
100 books
60 books

Answers

Answer:

300

Step-by-step explanation:

What is the perimeter of polygon LMNPQ

Answers

Answer: c for maps

Step-by-step explanation:

17.66 units is the perimeter of the polygon.

What is Perimeter?

The perimeter of a two-dimensional form is the space surrounding it. It represents the total length of the shape's sides. The units used to measure the sides of the form, such as meters, centimeters, inches, or feet, determine the units used to measure the perimeter.

To find the perimeter of the polygon LMNPQ, we need to add up the lengths of all the sides.

The distance formula for finding the distance between two points [tex](x_1, y_1)[/tex] and [tex](x_2, y_2)[/tex] is:

[tex]d = \sqrt{(x_2 - x_1)^2 + (y-2 - y-1)^2)[/tex]

Using this formula, we can find the lengths of each side of the polygon:

[tex]LM = \sqrt{(2 - 4)^2 + (4 - 2)^2} = \sqrt{8}\\MN = \sqrt{(5 - 2)^2 + (8 - 4)^2} = \sqrt{25}\\NP = \sqrt{(8 - 5)^2 + (4 - 8)^2}= \sqrt{25}\\PQ = \sqrt{(6 - 8)^2 + (2 - 4)^2} = \sqrt{8}\\QL = \sqrt{(4 - 6)^2 + (2 - 2)^2} = 2[/tex]

Therefore, the perimeter of the polygon LMNPQ is:

Perimeter = LM + MN + NP + PQ + QL

= √8 + √25 + √25 + √8 + 2

≈ 2.83 + 5 + 5 + 2.83 + 2

≈ 17.66

So, the perimeter of the polygon LMNPQ is approximately 17.66 units.

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Please help I suck at this kind of math
I really only need help with number three but if you could do it ll that would be awesome

On the coordinate plane shown below, points G and I have coordinates (6,4) and (3,2), respectively.
1 Design a strategy in which the Pythagorean theorem is used to calculate the straight line distance between points G and I on a coordinate plane. Use complete sentences to describe the strategy.
2 Use the Pythagorean theorem to determine the distance between the two points on the coordinate plane. In your final answer, include all of your calculations.
3 Use the distance formula and the coordinates of points G and I to prove that the Pythagorean theorem is an alternative method for calculating the distance between points on a coordinate plane. In your final answer, include all of your calculations.

Answers

Answer:

I am sorry, I am only in middle school... I am learning about like the questions I have been asking

Step-by-step explanation:

I really hope you get the question answered and get it correct


Help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answers

Answer:

B

Step-by-step explanation:

First you put all the variables with a negative exponent to the opposite side of the fraction, with the answer of 45m^2p^2v^16/15m^6p^8. You then simplify, or cancel out until the variable only remains on one side of the fraction. 3v^16/m^4p^6. So your answer is B

write a polynomial in factored form with solutions of ​

Answers

Answer:

The factored form of a polynomial means it is written as a product of its factors. The factors are also polynomials, usually of lower degree.

solve the inequality

Answers

Answer:

x>-1

Step-by-step explanation:

Subtract 0.7 from both sides

Marco recorded the cost of jeans at several stores in the mall:
$45, $65, $75, $45, $97, $88, $52, $67, $99, $35
Find the mean price of jeans at the mall.

Answers

i think the answer is sixty-five

Answer: 66.8
Mean Def: A mean is a average in a number to get the average you add up all the numbers and divide it by how many numbers their are.
Explanation:
All together the numbers equal 668.
How many numbers: 10
668/10=

66.8

How many ways can a person toss a coin 14 times so that the number of tails is between 11 and 13 inclusive

Answers

Answer:

Step-by-step explanation:

Probability is the possibility for an event to occur or not to occur.

The formula for a combination is:

n choose r = n! / (r! x (n-r)!)

Given

n=14

r= 11 to 13

Hence, we shall add up the cases for 11 through 13.

nCr

14C11 + 14C12 + 14C13

14!/11!(14-11)! + 14!/12(14-12)! + 14!/13(14-13)!

= 14!/11!•3! + 14!/12!•2! + 14!/13!•1!

= 14*13*12*11!/11!•(3*2*1) + 14*13*12!/12!•(2*1) + 14*13!/13!•(1*1)

= 2184/6+182/2+14/1

= 364+91+14

= 469 ways

Step-by-step explanation:

469 ways are the ways to I think so if the answer is correct plz make ma the brainliest

Find parametric equations which describe each curve. No particular orientation is required.

a. The line containing the points (1, 2) and (-3,8).
b. The circle with radius 3 and center (4,1).

Answers

Answer:

The equation of the line is [tex](x(t),y(t))=(1-4t,2+6t)[/tex] and the equation of the circle is [tex]F(t)= (3cos(t)+4,3sin(t)+1)[/tex].

Step-by-step explanation:

(a) Given: The given points are [tex](1,2)[/tex] and [tex](-3,8)[/tex].

To find: The parametric equation of line containing points [tex](1,2)[/tex] and [tex](-3,8)[/tex].

We know that the parametric equation of line containing [tex](x_{1} ,y_{1} )[/tex] and [tex](x_{2} ,y_{2} )[/tex] is given by [tex](x(t),y(t))=(x_{1}+(x_{2}-x_{1})t,y_{1}+(y_{2}-y_{1})t)[/tex] where [tex]t[/tex]∈[tex][0,1][/tex].

Now, [tex]x(t)=1+(-3-1)t[/tex]

i.e, [tex]x(t)=1-4t[/tex]

And, [tex]y(t)=2+(8-2)t[/tex]

i.e, [tex]y(t)=2+6t[/tex]

Hence, the required parametric equation of the line is [tex](x(t),y(t))=(1-4t,2+6t)[/tex].

(b) Given: The radius of circle is 3 and centre is [tex](4,1)[/tex].

To find: The parametric equation of circle with radius 3 and centre [tex](4,1)[/tex].

We know that parametric equation of circle with radius [tex]r[/tex] and centre [tex](h,k)[/tex] is given by [tex]F(t)= (x(t),y(t))[/tex] where [tex]x(t)=rcos(t)+h[/tex] and [tex]y(t)=rsin(t)+k[/tex].

Now, [tex]x(t)=3cos(t)+4[/tex]

[tex]y(t)=3sin(t)+1[/tex]

So, the parametric equation of circle having radius 3 and centre [tex](h,k)[/tex] is [tex]F(t)= (3cos(t)+4,3sin(t)+1)[/tex].

Hence, the required equation of the circle is [tex]F(t)= (3cos(t)+4,3sin(t)+1)[/tex].

Which value is the same as 6 tenths?

Answers

Answer:

6/10 or 0.6

Step-by-step explanation:

Answer:

0.6 or 60%

Step-by-step explanation:

Help please.
state the scale factor.

Answers

Answer:

1.25

Step-by-step explanation:

Answer:

1.25

Step-by-step explanation:

It is 1.25 because take two of the same sides, I will use 15.5 and 12.4 as an example. If you divide 15.5 by 12.4, you get 1.25. To check the answer just do the same for another side. <3

Percy buys tomatoes that cost $0.56 per pound. He pays $2.52 for the tomatoes.


Part 1 out of 3

Percy estimates he bought 5 pounds of tomatoes. Is Percy's estimate reasonable? Complete the explanation.


Use compatible numbers to estimate how many pounds of tomatoes he can buy.


{Answer choices: 25, 5, 35} tenths divided by {Answer choices: 5, 25, 10} tenths is __. His estimate {Answer choices: is reasonable, is not reasonable}

Answers

Answer:

1) We know that tomatoes cost 56c per the pound, and he estimates that he bought 5 pounds of tomatoes. If we multiply 5 by 0.56 we get 2.8, which means that if he purchased 5 pounds of tomatoes, he would have spent only 20c more than he did, which is pretty close. So yes, his estimate is reasonable

2) Well, i dont hav any clear amount of money he can spend so, just remember, if you have 3 pounds per say, you multiply 3 by 0.56. And then you can find your answer

Hope that this helped to some extent!

Answer:

Step-by-step explanation:

Answer choices: 25, 5, 35} tenths divided by {Answer choices: 5, 25, 10} tenths is __. His estimate {Answer choices: is reasonable, is not reasonable}

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