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 Smallille, 2,400 out of 20,000 workers are unemployed.In Bigtown, 6,750 out of 75,000 workers are unemployed. Which town has
viktelen [127]
2400/20000 = 0.12;
6750/75000 = 0.09;
Because 0.12 > 0.09, Smallille has a larger unemployed problems than Bigtown.
4 0
3 years ago
Simplify: 3/5x + x<br> Where 3 over 5 x plus x
hoa [83]
3/(5x) + x = 3/(5x) + x/1 * (5x)/(5x)
= 3/(5x) + 5x²/5x
= (3+5x²) / 5x
4 0
3 years ago
Read 2 more answers
Jeff has two sticker-printing machines. Each machine can print 42 stickers per minute. On day 1, only the first machine was used
Anna71 [15]

Answer:

c 89+42x+42y

Step-by-step explanation:

On day 1 :

First Machine= 89 stickers

Second Machine= none

On day 2 :

First Machine= ? stickers ( if in 1min = 42stickers

x min=?

( x min/1 min × 42stickers)

=42x stickers.

Second Machine=?stickers ( if in 1min = 42stickers

y min=?

( y min/1 min × 42stickers)

=42y stickers.

Total = 89 + 42x + 42y

5 0
2 years ago
Please help with this question<br> Only real answers please.
Evgesh-ka [11]

minimum (-2,-2)

hope this will help

6 0
3 years ago
06:20+35min=<br><br>06:23+ _ min=07:00
Katarina [22]

Answer:

27 min i think

Step-by-step explanation:

5 0
3 years ago
Read 2 more answers
Other questions:
  • What is the gcf of b3+5b2-20b
    7·1 answer
  • Write a paragraph proof for the following conjecture.
    9·1 answer
  • F(x) = 5x and g(x) = x + 11.
    10·2 answers
  • PLEASE HELP QUICKLY BEFORE I GO OFFLINE!! (EASY QUESTION)
    9·2 answers
  • The life span of a battery is the amount of time the battery will last. The distribution of life span for a certain type of batt
    13·1 answer
  • Kesha is choosing a 3 letter password from the letters ABCDE the password cannot have the same letter repeated in it how many su
    6·1 answer
  • James has a part-time job that pays $155 a week. If he has already saved $260, which inequality gives the minimum number of week
    8·2 answers
  • Two neighbors in a rural area want to know the dsitance between their homes in miles what should the mneighbors us as a conversi
    5·1 answer
  • Find the mean and the MAD.
    13·2 answers
  • What is 7x^2-8x-9=-3x rounded to the nearest hundredth
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!