+ Reply to Thread
Results 1 to 2 of 2

Thread: Little problem that I'm struggling to solve...

  1. #1
    Points: 4, Level: 1
    Level completed: 7%, Points required for next Level: 46

    Posts
    1
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Little problem that I'm struggling to solve...




    The proportion of smokers in a certain population is 25%. What is the probability
    that smokers' proportion in a sample of 40 people randomly selected from this
    population will be below (strictly less than) 20%.

    Surely you would use the binomial table N = 40 P = 0.25 X = 8 (since below 20% = less than 8 people from the sample of 40)

    I tried using the binomial table to find P(X<8) then use the binomial equation P(X=8).

    So to complete the question I did P(X<8) - P(X=8) = 0.1819.. and I thought 18.19% is the correct answer but I seem to be mistaken? Any help?

    The correct answer is 0.2296, why?

    Appreciate any help thanks!

  2. #2
    Points: 1,974, Level: 26
    Level completed: 74%, Points required for next Level: 26

    Location
    New Zealand
    Posts
    227
    Thanks
    3
    Thanked 48 Times in 47 Posts

    Re: Little problem that I'm struggling to solve...


    Book answers are not always right.

+ Reply to Thread

           




Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts






Advertise on Talk Stats