+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 28

Thread: Please can you check my answers

  1. #1
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Please can you check my answers




    Q1) A Newspaper dealer sells 1 newspaper every 6 mins on average. You can assume it follows a Poisson Distribution.

    a) Whats the probability that he sells exactly 3 newspaers in the next 6 mins? (My Answer: 0.83%)

    b) whats the probability he sells at least 3 newspapers in the next 12 mins?
    (My answer: 32.33%)

    c) The dealer has 1 newspaper left to sell. Whats the smallest length of time he must wait to be at least 94% sure of selling it? (My answer: 16mins 52.8 seconds)

    Q2) An electrical appliance lifetime follows a normal distribution with mean 530 hrs and SD 51 hrs. Calculate:

    a) percentage of components that fail in under 600 hrs (My answer: 8.53%)
    b) percentage that fail between 471 and 525 hrs (My answer: 33.72%)
    c) lifetime that components can exceed with 95% confidence (My answer 613.64 hrs)

    Q3) The journey to or from work has a mean of 67 minutes and a standard deviation of 15 minutes. You can assume a normal distribution of journey times.

    a) What's the probability the workers total traveling time to and from work is more than 151 minutes? (My Answer: 28.43%)

  2. #2
    Devorador de queso
    Points: 95,781, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Awards:
    Posting AwardCommunity AwardDiscussion EnderFrequent Poster
    Dason's Avatar
    Location
    Tampa, FL
    Posts
    12,933
    Thanks
    307
    Thanked 2,629 Times in 2,245 Posts

    Re: Please can you check my answers

    Hi. Do you have a question? It would be a good idea to read this.

  3. #3
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Please can you check my answers

    My question is:

    Are my answers correct or incorrect? And if incorrect please can you explain. Thanks

  4. #4
    Devorador de queso
    Points: 95,781, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Awards:
    Posting AwardCommunity AwardDiscussion EnderFrequent Poster
    Dason's Avatar
    Location
    Tampa, FL
    Posts
    12,933
    Thanks
    307
    Thanked 2,629 Times in 2,245 Posts

    Re: Please can you check my answers

    Your first one isn't right. I'm not going to just check all of your answers for you though. If you explain what you did to get each answer I would gladly tell you if you took the correct approach or where you went wrong (and heck if you do that much I probably would check your answers because you're actually showing some effort). But as it is I'm not compelled to just check them. But like I said your first answer isn't correct.

  5. #5
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Please can you check my answers

    How do I write mathematical symbols here? I am trying to write my working but its awkward.

  6. #6
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Please can you check my answers

    Q1a) By using this formula: http://www.bionicturtle.com/images/u...7F1lambda1.png

    where Landa = 1 and x=3

    I substituted the values in and got the answer 0.83%

  7. #7
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Please can you check my answers

    Q1b) P(x=>3)

    = 1 - P(x < 2)
    = 1 - [P(0) + P(1) + P(2)]
    Substituted the values in the formula
    = 1 - [0.1353+0.2707+0.2707]
    = 0.3233 => 32.33%

  8. #8
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Please can you check my answers

    I have written it in Paint
    Attached Images  

  9. #9
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Please can you check my answers

    Please can you check my answers
    Attached Images

  10. #10
    Devorador de queso
    Points: 95,781, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Awards:
    Posting AwardCommunity AwardDiscussion EnderFrequent Poster
    Dason's Avatar
    Location
    Tampa, FL
    Posts
    12,933
    Thanks
    307
    Thanked 2,629 Times in 2,245 Posts

    Re: Please can you check my answers

    Quote Originally Posted by zkm1223 View Post
    How do I write mathematical symbols here? I am trying to write my working but its awkward.
    This post should get you started with that.

  11. #11
    Devorador de queso
    Points: 95,781, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Awards:
    Posting AwardCommunity AwardDiscussion EnderFrequent Poster
    Dason's Avatar
    Location
    Tampa, FL
    Posts
    12,933
    Thanks
    307
    Thanked 2,629 Times in 2,245 Posts

    Re: Please can you check my answers

    Quote Originally Posted by zkm1223 View Post
    Q1a) By using this formula: http://www.bionicturtle.com/images/u...7F1lambda1.png

    where Landa = 1 and x=3

    I substituted the values in and got the answer 0.83%
    Then you're doing the math wrong somehow. You should be getting something like .0613. If you can't get that part it's going to be tough to get any of the remaining questions. Try to figure out where you were going wrong.

  12. #12
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Please can you check my answers

    Oh yeah, I have double checked it and I must have put something wrong in the calculator. I am getting 0.0613. Please can you check the rest of my answers.

  13. #13
    TS Contributor
    Points: 7,284, Level: 56
    Level completed: 67%, Points required for next Level: 66

    Location
    MD, USA
    Posts
    465
    Thanks
    8
    Thanked 11 Times in 11 Posts

    Re: Please can you check my answers

    He's kind of telling you to show your work and maybe even to explain your reasoning.

    Sometimes just writing down what you're doing and why you're doing it makes it clear to you what is wrong.
    Be wordy. Sleep on it if necessary. Don't panic; you'll get this, sooner or later.

    This forum is helpful. I wouldn't have stayed here if it weren't.

  14. #14
    Points: 1,318, Level: 20
    Level completed: 18%, Points required for next Level: 82

    Posts
    17
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Please can you check my answers

    I have shown my working in the attachments in posts 7, 8 and 9.

  15. #15
    Devorador de queso
    Points: 95,781, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Awards:
    Posting AwardCommunity AwardDiscussion EnderFrequent Poster
    Dason's Avatar
    Location
    Tampa, FL
    Posts
    12,933
    Thanks
    307
    Thanked 2,629 Times in 2,245 Posts

    Re: Please can you check my answers


    Q1 looks good. Haven't had time to check the others though.

+ Reply to Thread
Page 1 of 2 1 2 LastLast

           




Similar Threads

  1. Can you check my answers please?
    By SadieKhan in forum Probability
    Replies: 0
    Last Post: 01-09-2011, 06:27 AM
  2. Replies: 3
    Last Post: 12-19-2010, 10:59 PM
  3. Replies: 1
    Last Post: 11-10-2009, 12:16 AM
  4. Check my answers please?
    By Starrs in forum Statistics
    Replies: 1
    Last Post: 03-02-2008, 12:59 AM
  5. Please Help..(check answers)
    By Stunt101 in forum Statistics
    Replies: 2
    Last Post: 12-13-2006, 06:04 AM

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