Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    Hi,
    I'm having trouble with my stats homework. I didn't do statistics at a level so I'm really clueless at this.

    In London in April, the probability that it rains on any particular day is 0.3. Calculate the probability that:
    (i) It rains on each of the first 3 days in April. (State any assumptions you have made in order to carry out your calculation.)
    (ii) It rains on the first day and is dry for the next 3 days.

    Thanks in advance
    Offline

    15
    ReputationRep:
    (Original post by Blahblahblah96)
    ^
    i) consider the fact that for three days, it rains. The probability of it raining on each day is 0.3. So the probability of it raining on all three days is...

    (remember that you multiply probabilities in an AND scenario).

    ii) what's the probability of it NOT raining? Take this, and consider another AND situation where it doesn't rain on day 1, and does for three days.

    Solution in spoiler (try to give it a go first though).
    Spoiler:
    Show
    Let the probability that it rains = R = 0.3
    Therefore the probability it doesn't rain = R' = 1 - 0.3 = 0.7

    i) P = RRR = 0.33 = 0.027

    ii) P = R'RRR = 0.7 x 0.33 = 0.0189

    Hope I helped :cute:
 
 
 
Reply
Submit reply
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Updated: February 7, 2016
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Should Spain allow Catalonia to declare independence?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.