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
Nata [24]
3 years ago
13

Let X be a random variable that is equal to the number of times a 5 is rolled in three rolls of a fair 5-sided die with the inte

gers 1 through 5 on the sides. What is E[X2 ]? What is E2 [X], that is, (E[X])2 ? Justify your answers briefly.
Mathematics
1 answer:
Svetradugi [14.3K]3 years ago
7 0

Answer:

Step-by-step explanation:

Note: If you have any queries related the answer please do comment. I would be very happy to resolve all your queries.

Firstly we will make PMF

For X=0, P=(4/5)^3=64/125

For X=1, P=C(3,1)*(1/5)*(4/5)^2=3*16/125=48/125

For X=2, P=C(3,2)*(1/5)^2*(4/5)=3*4/125=12/125

For X=3, P=C(3,3)*(1/5)^3=1/125

So,

E[X^2]=1*48/125+2^2*(12/125)+3^2/125=0.84

E[X]=48/125+12/125*2+1/125*3=0.6

So,

E[X]^2=0.36

You might be interested in
in thailand the population of town is 48700 men and 41600 women what percentage of the total percentage are men
Finger [1]

Answer:

53.931339977852% (you can round)

Step-by-step explanation:

You add up 48,700 and 41,600 and you would get 90,300 as the overall population. Then you would put it in fraction form if you want to convert it into a percentage. The fraction form would be 48,700/90,300. You could simplify it to 487/903. Then you do  487            x      . You would cross multiply and get

                                              ___    =    ___

                                              903           100

903x = 48700. Then you would divide each side by 903 and get x = 53.931339977852% (you can round)

6 0
3 years ago
Read 2 more answers
The ratio of the height of a skateboard ramp to the length of the skateboard ramp is 1 to 3.The height of the ramp is 15 feet.Wh
SpyIntel [72]

Answer:

17ft

Step-by-step explanation:

8 0
3 years ago
HELP ASAP <br><br> What is the value of x?<br> O x = 55°<br> O x = 60°<br> O x = 70°<br> O x = 110°
valina [46]

Answer:

the answer is the answer the answer is x=55 degrees because the angle sum for a triangle is 180 degrees and because we are told angle A and angle C are congruent that means you can simply take 180 - 70 to get 110 and i simply divided that by 2 and got 55 degrees

Step-by-step explanation:

5 0
3 years ago
Two mechanics worked on a car. The first mechanic worked for
sergij07 [2.7K]
76.25 is the answer because 1525 divided by 20 equals 76.25
8 0
3 years ago
The weight of meteorite A is 5 times the weight of meteorite B. If the sum of their weights is 132 tons, find the weight of each
sladkih [1.3K]

Answer:

A: 105.6 B: 26.40

Step-by-step explanation:

if you divide 132 by 5, you get Meteorite B, 26.40, then minus that from 132, and you get Meteorite A, 105.6.

To check, do 26.40x5 and you should get 132.

3 0
3 years ago
Other questions:
  • Jose can read 7 pages of his book in 5 minutes. At this rate, how long will it take him to read the entire 175 page book?
    12·2 answers
  • Which is the smaller unit of measurement foot or yard???
    5·1 answer
  • Jimmy's class has 4 jump ropes, and their average length is 112 meters. one jump rope is 34 meters, the second jump rope is 1 me
    11·1 answer
  • Help solve 5/6n = 10
    7·2 answers
  • What are the answers too these questions
    7·1 answer
  • You buy a shirt for $19.95 and a pair of shorts for $35.95. Shirts are on sale for 25% off and shorts are on sale for 30% off. W
    15·1 answer
  • Jane charges a flat fee of $12 when she babysits plus $8 extra each
    10·1 answer
  • How do the number line graphs of the solutions sets of -23 &gt; X and X2-23 differ?
    9·2 answers
  • Find the area of the shape.
    6·1 answer
  • I know the answer to the question. It’s just whenever I answer the reason for my answer it gets no marks. Can someone explain ho
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!