Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

Leaving Cert HL Maths Probability

Options
  • 18-01-2015 2:28pm
    #1
    Troxck
    Closed Accounts Posts: 1,386 ✭✭✭


    My Maths teacher gave us a handout of Stats and Probability questions, while I could get the Stats and easy Probability questions, there are some I could not even start! The pictures added below are the ones which are causing difficulty. If any of ye could give me a hand as to how to even start them, that would be brilliant!

    One

    Two

    Three


Comments

  • Options
    #2
    Peregrine
    Moderators, Education Moderators Posts: 26,399 Mod ✭✭✭✭Peregrine


    Half the chocolates in the box are milk chocolates so the probability that it's a milk chocolate is 0.5 and the probability that it's either dark or white is 0.5.

    Out of the 0.5 probability that it's either a dark or white chocolate, there's a 1/3 probability that it's white and a 2/3 probability that it's dark.

    So overall:
    0.5 milk
    0.5*2/3 = 1/3 dark
    0.5*1/3 = 1/6 white
    =1


  • Options
    #3
    is mise spartacus
    Registered Users Posts: 1,027 ✭✭✭is mise spartacus


    I see your issue. There is a new section in the course on hypothesis testing (used for part e) we have to know it unfortunately. This is how I would get round part E

    95% of the population lies within 1.96 standard deviations of the mean

    Null hypothesis is 350g
    348 +/- 1.96 × 8÷√50
    Z score= 348-350 over 8÷√50 = -1.7677
    -1.96<Z<1.96

    I'm not sure if this is correct


Advertisement