Determine the mean and variance of the random variable with the following probability mass function. f(x)=(216/43)(1/6)x, x=1,2,3 Round your answers to three decimal places (e.g. 98.765).

Answers

Answer 1

Mean:

E[X] = ∑ x f(x) = 1 × f (1) + 2 × f (2) + 3 × f (3) = 51/43 ≈ 1.186

Variance:

Recall that for a random variable X, its variance is defined as

Var[X] = E[(X - E[X])²] = E[X ²] - E[X

Now,

E[X ²] = ∑ x ² f(x) = 1² × f (1) + 2² × f (2) + 3² × f (3) = 69/43

Then

Var[X] = 69/43 - (51/43)² = 366/1849 ≈ 0.198

(each sum is taken over x in the set {1, 2, 3})


Related Questions

Can you help with this

Answers

9514 1404 393

Answer:

  D, C

Step-by-step explanation:

The only two rational expressions that have appropriate denominators are ...

  1/(x² +6x) . . . contributes a factor of x to the denominator

  (x+2)/(x² -36) . . . contributes a factor of (x -6) to the denominator

The proper order in the expression is ...

  [tex]\displaystyle\dfrac{x+2}{x^2-36}-\dfrac{1}{x^2+6x}=\dfrac{x^2+x+6}{x(x-6)(x+6)}[/tex]

Answer:

(x+2/x^2-36) - (1/x^2+6x) = (x^2+x+6/x(x-6)(x+6))

Step-by-step explanation:

I hope that helps

Ed makes $11.50 an hour. This week he worked 36 regular hours and 7 hours at time and a half?

Answers

494.5 (might be wrong-)

Please look below (Please Explain and NO LINKS)

Answers

Answer:

Mean = Sum of all numbers divided by the amount of numbers

[tex]Mean/Average=\frac{3+1+1.5+1.25+2.25+4+1+2}{8} =\frac{16}{8} =2[/tex]

Median = the middle number when the ordered from least to greatest.

From least to greatest: [tex]1, 1, 1.25, 1.5, 2, 2.25, 3, 4[/tex]The two middle numbers are 1.5 and 2.

If there are two middle numbers, find the mean/average of those numbers:

[tex]\frac{1.5+2}{2} =\frac{3.5}{2} =1.75[/tex]

Therefore, the answer would be:

Mean = 2Median = 1.75

solve above question​

Answers

y=2−3x

2 Substitute
y
=
2

3
x
y=2−3x into
x
+
y
=
7
x+y=7.

2
x
+
2
=
7
−2x+2=7

3 Solve for
x
x in

2
x
+
2
=
7
−2x+2=7.
x
=

5
2
x=−
2
5



4 Substitute
x
=

5
2
x=−
2
5

into
y
=
2

3
x
y=2−3x.
y
=
19
2
y=
2
19



5 Therefore,
x
=

5
2
y
=
19
2



x=−
2
5


y=
2
19




The sum of 'n' terms of an arithmetic sequence is 4n2+3n. What is the first term, the common difference, and the sequence?

Answers

Answer:

Step-by-step explanation:

If the 2 is an exponent, it should be indicated with a circumflex:  4n^2+3n.

What is the first term?

a₁ = S₁ = 4·1² + 3·1 = 7

:::::

What is the common difference?

a₁ + a₂ = S₂ = 4·2² + 3·2 = 22

a₂ = 22-a₁ = 15

common difference d = a₂ - a₁ = 8

:::::

What is the arithmetic sequence?

The nth term is 7+(n-1)d = 7+(n-1)8 = 8n-1.

a₁ = 8·1-1 = 7

a₂ = 8·2-1 = 15

a₃ = 8·3-1 = 23

...

A health club sold ten memberships in one week for total of $3000. If male memberships cost $300 and female memberships cost $300, then how many male memberships and how female memberships were sold?

Answers

Answer:

Step-by-step explanation:

The reason you haven't gotten an answer to this is because in its current formatting, there is no answer. Here's what I mean:

The first equation is going to be concerning the NUMBER of memberships sold, where m is male and f is female. The total number of memberships was 10:

m + f = 10

Now for the money equation. The total amount of money made from that number of memberships was 3000, where male memberships cost $300 and so do the female memberships, giving us an equation of

300m + 300f = 3000

Go back to the first equation and solve for either m or f. I solved for m in terms of f:

m = 10 - f and sub that into the second equation for m to get:

300(10 - f) + 300f = 3000 and

3000 - 300f + 300f = 3000. Here is where you find the problem. The -300f and the 300f cancel each other out, leaving you with the fact that

3000 = 3000 which it does, but it doesn't give us any viable answer.

I would have to say that since we can't do math on this, that the most credible answer you'll find is that the same number of male and female memberships were sold because 5 male memberships cost $1500 (5 memberships at $300 a piece is $1500) and 5 female memberships also cost $1500.

1500 + 1500 = 3000

. Two mutually exclusive projects have projected cash flows as follows:
YEAR PROJECT A PROJECT B
0 Ksh. -2m Ksh. -2m
1 1m 0
2 1m 0
3 1m 0
4 1m 6m





Required:
a) Determine the internal rate of return for each project. [2 Marks]

b) Determine the net present value for each project at discount rates of 0, 5,10,20,30, and 35 percent. [2 Marks]

c) Plot a graph of the net present value of each project at the different discount rates. [2 Marks]

d) Which project would you choose? Why? [ 2 Marks]

e) What is each project’s MIRR if the cost of capital is 12 percent?

Answers

Answer:

yes

Step-by-step explanation:

please help with this on the picture

Answers

Answer:

There is not enough information to solve this problem :(

Find m∠DFC.

A. 23
B. 167
C. 46
D. 69

Answers

Answer:

A.23

maaf kalosalah !(!)!(!)!(!)!(!)!(!)!(!)!(!)!(!)!

Simplify the following expression:
(15b^5)^2
—————-
(5b^2)^3

Answers

Answer:

5x

Step-by-step explanation:

(75b x)x×2

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

(10b x)×3

=75b x×x×2

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

10b x×3

=25x

-------

5

=5x

Do the two trapezoids in the figure appear to be similar? Why or why not?
options:

A)

They're not similar because only one pair of corresponding angles in the two trapezoids is congruent.

B)

They're similar because two pairs of corresponding angles in the two trapezoids are congruent.

C)

They're similar because one pair of corresponding angles in the two trapezoids is congruent.

D)

They're not similar because two pairs of corresponding angles in the two trapezoids are congruent.

Answers

Answer:

Option B,

They're similar because two pairs of corresponding angles in the two trapezoids are congruent

Answer:

They're not similar because only one pair of corresponding angles in the two trapezoids is congruent.

Step-by-step explanation:

HELP ME PLSSS SUMMER SCHOOL A HARD

Answers

Answer:

y=2x+8

Step-by-step explanation:

Hope this helps

Instructions: Determine whether the lines
passing through the pairs of points are
parallel, perpendicular or neither.
• Line a: (5,3) and (5,7)
• Line b: (2,7) and (-1,7)
Select one:
O Perpendicular
Neither
Parallel

Answers

Answer: Perpendicular

Explanation

the gradient of line b is (7-7)/(-1-2) = 0/-3 = 0

Therefore it means that it is a horizontal line

Must click thanks and mark brainliest

Factorize (256⁴-1).
Use appropriate identity.

Answers

(256⁴-1)

= (256-1)⁴

Using identity (a-b)⁴ = a⁴−4a³b+6a²b²−4ab³+b⁴

Let a be 256 and b be 1

Then

256⁴−4(256)³(1)+6(256)²(1)²−4(256)(1)³+(1)⁴

After solving

(256²-1)²

(a-b)² = a²-2ab+b²

256²-2×256×1+1²

= (256²-1)(256²+1)

Must click thanks and mark brainliest

Answer:

Use identity:

a² - b² = (a + b)(a - b)

Consider that:

256 = 2⁸

Now factorize:

256⁴ - 1 = (2⁸)⁴ - 1 = 2³² - 1 = (2¹⁶ - 1)(2¹⁶ + 1) = (2⁸ - 1)(2⁸ + 1)(2¹⁶ + 1) = (2⁴ - 1)(2⁴ + 1)(2⁸ + 1)(2¹⁶ + 1) = (2² - 1)(2² + 1)(2⁴ + 1)(2⁸ + 1)(2¹⁶ + 1) = (2 - 1)(2 + 1)(2² + 1)(2⁴ + 1)(2⁸ + 1)(2¹⁶ + 1)


In the equation 11 - 4(x +4) = 6x, the first step is to simplify 11 - 4.
True
False

Answers

Answer:

False

Step-by-step explanation:

You first need to distribute the -4 to (x+4).

if 2 shirts cost 18.80, how much would 9 shirt cost.

Answers

Answer:

84.60

Step-by-step explanation:

We can write a ratio to solve

18.80             x

---------   = --------------

2 shirts    9 shirts

Using cross products

18.80 *9 = 2x

169.2 =2x

Divide each side by 2

169.2/2 =2x/2

84.60 =x

What is the greatest common factor of 10 and 13?
ANSWER IN LESS THEN 3 MINS AND I'LL GIVE BRAINLIEST

Answers

Answer:

the answer for this would be 1

Political Stcibility​

Answers

Answer:

Political stability is a variable of great importance in a country's evolution since, across time, it was identified as causing law level of economic growth, but also it was presented as a consequence of poor economic development.

write all the prime numbers between 10 and 30.​

Answers

It's 11, 13, 17, 19, 23 and 29.

Answer please I’m stuck

Answers

Answer:

196

Step-by-step explanation:

We will use the formula:

Surface Area of A / Surface area of B = (Height of A /Height of B)^2

49/S2 = (4/8)^2

49/S2 = 1/4

S2 = 196

Answred by Gauthmath

how many itegers from 15 to 85, inclusive are multibles of 8

Answers

Answer:

9

Step-by-step explanation:

First multiple of 8 in that range is 8(2)=16.

The last multiple of 8 in that range is 8(10)=80.

So we just need to find how many numbers there are between 2 and 10. inclusive.

10-2+1=9

It's also not that long to write out and count.

1-2

2-3

3-4

4-5

5-6

6-7

7-8

8-9

9-10

9 numbers there are

Multiply those 9 numbers by i you will have all multiples of 8 btw 15 and 85.

8(2)=16

8(3)=24

8(4)=32

8(5)=40

8(6)=48

8(7)=56

8(8)=64

8(9)=72

8(10)=80

Given the numbers 30 and 45, find the common factors of the two numbers.​​

Answers

Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30

Factors of 45: 1, 3, 5, 9, 15, 45

The common factors between the two numbers are 1, 3, 5, 15.

Hope this helps!

Kevin made a business trip of 312.5 miles. He averages 60 mph for the first part of the trip and 55 mph for the second part. If the trip took a 5.5 hours how long did he travel at each rate

Answers

Answer:

Kevin travels for 2 hours at 60 mph and 3.5 hours at 55 mph

Step-by-step explanation:

Let's say that Kevin spends x hours going 60 mph and y hours going 55 mph. We can say that the sum of the two parts is 5.5, so x+y = 5.5 . Next, he goes 60 miles per hour for the first part of the trip, so for each hour he goes 60 mph, he travels 60 miles. We can then denote 60 * x as the distance traveled during the first part of his trip as he goes 60 mph for x hours. Similarly, 55 * y denotes the distance Kevin travels during the second part of his trip. His total distance is thus 60 * x + 55 * y = 312.5 miles

We have

x + y = 5.5

60 * x + 55 * y = 312.5

One way we can solve this is to solve for y in the first equation and plug that into the second. Subtracting x from both sides in the first equation, we get

y = 5.5 - x

Plugging that into the second equation, we get

60 * x + 55 * (5.5-x) = 312.5

60 * x + 55 * 5.5 - 55x = 312.5

5x  +302.5 = 312.5

subtract 302.5 from both sides to isolate the x and its coefficient

5x = 10

divide both sides by 5 to solve for x

x = 2

y = 5.5 - x = 5.5 - 2 = 3.5

Therefore, Kevin travels for 2 hours at 60 mph and 3.5 hours at 55 mph

hi hi hi please help ‍♀️

Answers

Answer:

Cooper read the least because

Step-by-step explanation:

1/5 is less than

Answer: Cooper read more

Step-by-step explanation:

What is the slope-intercept equation of the line below?

Answers

Answer:

y=-5/4x+3

Step-by-step explanation:

y=mx+c

m = (y1-y2)/(x1-x2) =(-2-3)/(4-0) =-5/4

sub the values y=3, x=0 to find c,

3 =-5/4(0) + c

c = 3

Find mPMA + mCMT. Please help..

Answers

PMA = 37

CMT =  101 - 54 =47

Total = 37 + 47 = 84

Answer: A. 84

Solve this pleaseeeeeeeeeee

Answers

Answer:

10d

Step-by-step explanation:

5d on 1 side, double it to get 10d cuz from Point O to Point D, y increases from 0 to 5d and since the triangles are congruent, we can add another 5d (or in total 10d).

Someone help me please

Answers

Answer:

y=4

Step-by-step explanation:

The triangle on the right is a 30-60-90 triangle

The ratio of sides in a 30-60-90 triangle is 1:√3:2

y:x:8

SO y will be 4 because 8/y=2/1

 In one of the examples he is working on, he knows that the two coordinates (0,6) and
(8, 10) are on the function that he is deriving. Using the information from these two
coordinates, determine the slope and y-intercept of the function Mike is looking for, and
then write out the correct function.

Answers

9514 1404 393

Answer:

  y = 1/2x + 6

Step-by-step explanation:

The slope m is given by the formula ...

  m = (y2 -y1)/(x2 -x1)

  m = (10 -6)/(8 -0) = 4/8 = 1/2

The y-intercept is given by the formula ...

  b = y -mx

  b = 6 -(1/2)(0) = 6

Then the slope-intercept equation is ...

  y = mx +b

  y = 1/2x +6

Find the length of the segment indicated. circles 4

Answers

I need more information, comment on my "answer".

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