Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Johnmathstudent

  • one year ago

If I flip four coins what is the probability that at least two of the coins are heads?

  • This Question is Open
  1. Johnmathstudent
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Please help

  2. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    its the opposite of P(at most 1 is heads)

  3. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    1 - P(0) - P(1)

  4. MAYSTEPH
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    do you have choices

  5. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    there are 16 outcomes tttt ttth ttht thtt httt ... 1 4 6 4 1 = 16 0 heads is 1 out of 16 1 head is 4 out of 16

  6. Johnmathstudent
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    What about at least 2 heads

  7. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    at least 2 heads means that you have 2, 3, or 4 heads P(0) + P(1) + P(2) + P(3) + P(4) = 1 P(2) + P(3) + P(4) = 1 - P(0) - P(1)

  8. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    since P(0) = 1/16 and P(1) = 4/16 the solution is determined

  9. Johnmathstudent
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So what would the answer be written as?

  10. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    im not going to do the subtraction for you ....

  11. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you can tell me what you get ... and i can verify if you did it correctly

  12. MAYSTEPH
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    bro your even confusing me.... amistre64

  13. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    im not a mind reader, so youll have to be more detailed in what is confusing :)

  14. MAYSTEPH
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    nevermind .. the probability would be 50% John

  15. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    the probability is not 50%; for starters, a probability is a number between 0 and 1 ... not a percentage.

  16. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    and for another, 1 - P(0) - P(1) does not equal .5000 or 1/2

  17. MAYSTEPH
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    he asked for a probability. if you flip 4 coins and the odds of 2 of the comming out heads is 2/4 and tht equals 50% and wtf is p

  18. MAYSTEPH
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    its not rocket science he just wants a simple answer.. idk whats wrong with tht

  19. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\binom{4}{0}.5^0.5^4+\binom{4}{1}.5^1.5^3+\binom{4}{2}.5^2.5^2+\binom{4}{3}.5^3.5^1+\binom{4}{4}.5^n.4^0=1\] \[(1).5^0.5^4+(4).5^1.5^3+(6).5^2.5^2+(4).5^3.5^1+(1).5^4.5^0=1\]

  20. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    P(E) is notation for "probability of an event"

  21. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    the last 3 terms are 4 choose 2, 4 choose 3, and 4 choose 4 which is what we want if we are to determine "at least 2" out of 4

  22. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    subtracting the first 2 terms from each side gives us the solution

  23. MAYSTEPH
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    your making this way more complex than it already isnt lol if you know the damn answer then tell him and quit arguing with a degenerate!

  24. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    i suggest you tone down your language. and, we are not providing a free answering service, we are offering a way to learn the material.

  25. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    my first attempt was to simplify it .... since that did not work i resorted to the longer, more detailed version of it all.

  26. Johnmathstudent
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So the answer is .6875?

  27. Johnmathstudent
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Or 11/16

  28. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    11/16 is correct either way is fine, but the format is up to whoever is doing the grading.

  29. Johnmathstudent
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thanks I just forgot how to do this from the beginning of the year

  30. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you did fine :) good luck

  31. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.