Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Syamantak

  • 2 years ago

Probability of Rain on a Day=0.2 What is the probability of raining atleast 2 days in a week ?

  • This Question is Open
  1. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    there are 2 ways to approach this

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

    out of 7 days in a week, it would be easier to calculate the compliment statement of: P(rain at most 1 day out of 7)

  3. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    P(0) + P(1)

  4. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    ... or is the compliment; does not rain at most 1 day out of the week?

  5. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    P(0) + P(1) at most 1 day of rain P(2) + P(3) + P(4) + P(5) + P(6) + P(7) at least 2 days of rain in any case .... the long way is: \[\sum_{2}^{7}~\binom{7}{r}~.2^r~.8^{7-r}\]

  6. Syamantak
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @amistre64 how do we solve the equation ?

  7. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    im thinking the 1 - P0+P1 is quicker "by hand"\[1-\binom{7}{0}~.2^0.8^7-\binom{7}{1}~.2^1.8^6\]

  8. Syamantak
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Actually I don't know summation and other things could you give it to me in a simple version @amistre64

  9. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    the (7 0) is just another way to write 7 "choose" 0, by this time you should have already gone thru the permuatation and combination material 7 C 0 is a common notation, but some texts use C(7,0) does any of that look familiar?

  10. Syamantak
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No,nothing looks familiar to me.Could you write the equation in a multiplication/addition/division/subtraction format @amistre64

  11. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    I already did. But if you do not know how to determine the number of ways to choose 0 from a set of 7, or the number of ways to choose 1 from a set of 7; then you really need to go back and review that material. The rest of the setup is elementary ....

  12. Syamantak
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Can you solve the equation step by step @amistre64

  13. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    not without having to try to teach you a chapters worth of material first. consider this tho: if you have 7 things in front of you, what is the number of ways you can simply walk away and choose none of them?

  14. Syamantak
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\infty \] ways

  15. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    :) there is really only 1 way to choose none of them, the choice to walk away is only 1 option. 7 "choose" 0 is equal to 1; in fact anything "choose" 0 = 1

  16. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    how, consider these 7 things, but you can only choose one of them; how many ways is there to choose 1 of them?

  17. Syamantak
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    7 ways

  18. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    lets have 7 things to choose from: a b c d e f g we can choose a or we can choose b or we can choose c or we can choose d or we can choose e or we can choose f or we can choose g 7 "choose" 1 is equal to ..7 do you agree?

  19. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    oh, you do agree :) good.

  20. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    now we can do the elementary stuff \[ 1 - (1~.2^0~.8^7+7~.2^1~.8^6)\]

  21. Syamantak
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ok so what will it be ?

  22. amistre64
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    most likely it will be whatever the calculator generates as an answer for you after you punch in the correct keys :/

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

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

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.