1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Feliz [49]
3 years ago
7

Consider the discrete random variable X given in the table below. Calculate the mean, variance, and standard deviation of X . Al

so, calculate the expected value of X . Round solution to three decimal places, if necessary. x 6 8 9 15 P ( x ) 0.64 0.14 0.14 0.08 μ = σ 2 = σ = What is the expected value of X ? E ( X )
Mathematics
1 answer:
Sindrei [870]3 years ago
6 0

Answer:

Expected value or mean = E(x) = \mu = 7.42

Variance = \sigma^2 = 6.283

Standard deviation = \sigma = 2.506

Step-by-step explanation:

We are given the following information:

x       |      P(x)

6       |     0.64

8       |     0.14

9       |     0.14

15     |     0.08

The expected value or mean is given by

E(x) = \mu = x \cdot P(x) \\\\E(x) = \mu = 6 \cdot 0.64 + 8 \cdot 0.14 + 9 \cdot 0.14 + 15 \cdot 0.08 \\\\E(x) = \mu = 7.42

The variance is given by

\sigma^2 = \sum (x - \mu)^2 \cdot p(x)

\sigma^2 = (6 - 7.42)^2 \cdot 0.64 + (8 - 7.42)^2 \cdot 0.14 + (9 - 7.42)^2 \cdot 0.14 + (15 - 7.42)^2 \cdot 0.08 \\\\\sigma^2 = 1.291 + 0.0471 + 0.349 + 4.596 \\\\\sigma^2 = 6.283

The standard deviation is given by

\sigma = \sqrt{\sum (x - \mu)^2 \cdot p(x)} \\\\\sigma = \sqrt{\sigma^2} \\\\\sigma = \sqrt{6.283} \\\\\sigma = 2.506

Therefore,

Expected value or mean = E(x) = \mu = 7.42

Variance = \sigma^2 = 6.283

Standard deviation = \sigma = 2.506

You might be interested in
Pls answer with equation
mel-nik [20]

Answer:

127°

Step-by-step explanation:

171+62+127=360

3 0
3 years ago
Read 2 more answers
If a circle has a radius of 13 and a sector defined by a 7.4 degree arc, what is the area, in cm^2, of the sector?
Rufina [12.5K]
Pretty sure you do 7.4/360. And then times pi and the radius squared. Should come out to be 10.91354 cm^2
5 0
3 years ago
Kevin and Marcus were comparing their ages. The same of their ages was at least 9 years but was at most 24 years. If Kevin is 6
saul85 [17]

<em><u>The inequality that represent age of marcus is:</u></em>

24\geq 6+m\geq 9

<em><u>The possible values for age of Marcus is:</u></em>

m = 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18

<em><u>Solution:</u></em>

Given that,

The sum of ages of Kevin and Marcus was at least 9 years but was at most 24 years

Kevin is 6 years old

Let "m" be the age of Marcus

Thus we frame a inequality as:

24\geq \text{ sum of ages } \geq 9

at least 9 years means that "greater than or equal to 9"

at most 24 years means "less than or equal to" 24

From given,

Sum of ages = kevin age + marcus age

Sum of ages = 6 + m

Thus the inequality is:

24\geq 6+m\geq 9

Solve the inequality

\mathrm{If}\:a\ge \:u\ge \:b\:\mathrm{then}\:a\ge \:u\quad \mathrm{and}\quad \:u\ge \:b\\\\24\ge \:6+m\quad \mathrm{and}\quad \:6+m\ge \:9\\\\Solve\ them\ separately

24\ge \:6+m\\\\\mathrm{Switch\:sides}\\\\6+m\le \:24\\\\\mathrm{Subtract\:}6\mathrm{\:from\:both\:sides}\\\\6+m-6\le \:24-6\\\\\mathrm{Simplify}\\\\m\le \:18

Now solve another inequality

6+m\ge \:9\\\\\mathrm{Subtract\:}6\mathrm{\:from\:both\:sides}\\\\6+m-6\ge \:9-6\\\\\mathrm{Simplify}\\\\m\ge \:3\\\\\mathrm{Combine\:the\:intervals}\\\\m\le \:18\quad \mathrm{and}\quad \:m\ge \:3\\\\\mathrm{Merge\:Overlapping\:Intervals}\\\\3\le \:m\le \:18

24\ge \:6+m\ge \:9\quad :\quad \begin{bmatrix}\mathrm{Solution:}\:&\:3\le \:m\le \:18\:\\ \:\mathrm{Interval\:Notation:}&\:\left[3,\:18\right]\end{bmatrix}

<em><u>Thus possible values for age of Marcus is:</u></em>

m = 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18

4 0
2 years ago
The scale factor on a scale drawing of machine part is 15 1 /8. If the part is 3 7/8 inches long as the drawing, how long is the
Marta_Voda [28]

Answer:

Option D) 58 39/64 inches​

Step-by-step explanation:

we know that

The scale drawing is

15\frac{1}{8}

convert to an improper fraction

15\frac{1}{8}=\frac{15*8+1}{8}=\frac{121}{8}

That means

121 in in the actual, represent 8 in on a scale drawing

To find how long is the actual part for 3 7/8 inches long as the drawing

Apply proportion

First convert to an improper fraction

3\frac{7}{8}=\frac{3*8+7}{8}=\frac{31}{8}

\frac{121}{8}\frac{actual}{drawing} =\frac{x}{(31/8)}\frac{actual}{drawing}\\ \\x=121(31/8)/8\\ \\x=\frac{3,751}{64}\ in  

convert to mixed number

\frac{3,751}{64}\ in=\frac{3,712}{64} +\frac{39}{64} =58\frac{39}{64}\ in

7 0
3 years ago
30 POINTS! Please answer and show work for both!
monitta

The recommended approach for such equations is to eliminate fractions first, by multiplying by the LCM of the denominators. You can simply simplify, then work them as a 2-step linear equation, doing your arithmetic with the fractions as they are.

a) (5x-1)/7 + (4x-3)/2 -(3-2x)/2 = 6 . . . . . given

... 2(5x -1) +7(4x -3) -7(3 -2x) = 84 . . . . . multiply by 14

... 10x -2 +28x -21 -21 +14x = 84 . . . . . . eliminate parentheses

... 52x -44 = 84 . . . . . . . . . . . . . . . . . . . . collect terms

... 52x = 128 . . . . . . . . . . . . . . . . . . . . . . . add 44

... x = 32/13 . . . . . . . . . . . . . . . . . . . . . . . . divide by 52 and simplify

b) (4x−3)/2 − (5−2x)/3 − (3x−4)/3 = 5 . . . given

... 2x -3/2 -5/3 +(2/3)x -x +4/3 = 5 . . . . . . .eliminate parentheses

... (5/3)x -11/6 = 5 . . . . . . . . . . . . . . . . . . . . simplify

... (5/3)x = 41/6 . . . . . . . . . . . . . . . . . . . . . . add 11/6

... x = (41/6)/(5/3) = 41/10 . . . . . . . . . . . . . .divide by the coefficient of x

_____

Using the first method, you're dealing with integers and you can do a lot of the math in your head. Using the second method, you're dealing with fractions and mixed numbers. A calculator can be helpful, especially if it handles arithmetic with fractions nicely, as many graphing calculators do.

6 0
3 years ago
Other questions:
  • I need help please.
    7·1 answer
  • Mr. Townes created a 2-foot wide garden path around a circular garden. The radius of the garden is 7 feet. He wants to cover the
    9·1 answer
  • How would I graph 2x+3y=−9
    14·1 answer
  • Your estimate of the market risk premium is 9%. The risk-free rate of return is 4% and General Electric has a beta of 0.7. Accor
    5·1 answer
  • The coordinate of point R and S are (4,3)and(1,6)what is the distance between the point
    12·1 answer
  • How do you solve 4 x 2 = 5?
    12·1 answer
  • Assume that females have pulse rates that are normally distributed with a mean of mu equals 75.0 beats per minute and a standard
    8·1 answer
  • What's the least common multiple of 9 and 15
    14·1 answer
  • 20 pts for whoever can answer the question on t picture
    13·1 answer
  • A mom mixes 9 ounces of juice with 3 ounces of water.What percent of the drink is juice .
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!