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
Andrews [41]
3 years ago
8

A binomial discrete random variable, X has a mean

Mathematics
1 answer:
kompoz [17]3 years ago
5 0

Since <em>X</em> follows a binomial distribution, its mean and variance are

<em>np</em> = 3

<em>np</em> (1 - <em>p</em>) = 2

Substitute <em>np</em> = 3 in to the second equation to solve for <em>p</em> :

3 (1 - <em>p</em>) = 2

1 - <em>p</em> = 2/3

<em>p</em> = 1/3

Solve for <em>n</em> :

<em>n</em> (1/3) = 3

<em>n</em> = 9

You might be interested in
Simplify. cos^2[(pi/2) - x] + cos^2[(pi/2) - x] + cos^2x
Ipatiy [6.2K]

Numerator
<span><span>cos<span>(<span>π/2</span>−x)</span></span>=<span>cos<span>(<span>π/2</span>)</span></span><span>cosx</span>+<span>sin<span>(<span>π/2</span>)</span></span><span>sinx</span></span>

now <span><span>cos<span>(<span>π/2</span>)</span></span>=0 and <span>sin<span>(<span>π/2</span>)</span></span>=1</span>

simplifies to : 0 + sinx = sinx

Denominator

<span><span>sin<span>(<span>π/2</span>−x)</span></span>=<span>sin<span>(<span>π/2</span>)</span></span><span>cosx</span>+<span>cos<span>(<span>π/2</span>)</span></span><span>sinx</span></span>

simplifies to : cosx + 0 = cosx

<span>⇒<span><span>cos<span>(<span>π/2</span>−x)</span></span><span>sin<span>(<span>π/2</span>−x)</span></span></span>=<span><span>sinx/</span><span>cosx</span></span>=<span>tan<span>x</span></span></span>

5 0
4 years ago
fermium-253 has a half-life of three days. a sample contains 400 g. how long will it take for the sample to decay to 100 g?
sladkih [1.3K]
This is a relatively easy half life calculation.
After one half-life period, half of the isotope remains.
After two half-life periods, one quarter of the isotope remains.
That being the case, we see this will take 2 half-life periods or 6 days.


6 0
3 years ago
Read 2 more answers
Can someone help me with numbers 18 and 20? thank you!
alekssr [168]

Answer:

18. x= 15

19. x = 32.5

20. 82.097

Step-by-step explanation:

because any trianglw with 65 degrees the other abgle will be equal making the side equal as well

180-115= you know

6 0
4 years ago
PLEASE HELP!!! THIS IS FOR MATH
Flauer [41]

Answer:

the answer is D.........

Step-by-step explanation:

I dont really have a reason that just seem like the best answer..... I hope it's right

5 0
3 years ago
ASAP PLS HELP ME FOR ALL IF THESE! 7, 8, 9.A and b (SHOW WORK!!)
tigry1 [53]
The answer for 8 should be c because it is a discount so you get to pay less.
4 0
4 years ago
Other questions:
  • The reading speed of sixth-grade students is approximately normal, with a mean speed of 125 words per minute and a standard devi
    11·1 answer
  • Help! Steve needs to find the product of two numbers. One of them is 6. The answer also needs to be 6. How will you solve this p
    10·2 answers
  • -2x squared plus x squared
    13·1 answer
  • What is the area of the rectangle? Round to the nearest square inch.
    12·1 answer
  • PLEASE HELP ME Imani spent half of her weekly allowancw playing mini-golf. To earn more money her parents let her wash the car f
    13·1 answer
  • Write in slope-intercept form an equation of the line that passes through the points (−5,−3) and (3,−11)
    6·1 answer
  • Rosa is converting a unit of measure in one system to a unit of measure in another system (1, 760yd)/(1mj) * (0.914m)/(1yd) * (1
    9·2 answers
  • Please help me with this and explain how you got your answer thank you!!
    5·2 answers
  • I need help on this slope problem-
    5·1 answer
  • Find the slope and reduce.<br> P=(2, 3) Q=(9, 7)<br> Slope =
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!