Sponsored Ads
D.W. Simpson
Worldwide Actuarial Recruitment
Life Health Pension Casualty US Asia Australia Europe Salary Apply
Ezra Penland Actuarial Recruiters
Top Actuary Jobs
Salary Surveys Apply Bios Casualty Health Life Pension
Pauline Reimer, ASA, MAAA
Pryor Associates
Actuarial Openings: Life, P&C, Health, Pensions, Finance
Advertise Here
Contact us at actuary@actuary.com or 770-425-8576
Reach top actuarial professionals

Results 1 to 6 of 6

Thread: Question about May 1992, Problem 12

  1. #1
    Actuary.com - Level II Poster
    Join Date
    Mar 2005
    Location
    United States
    Posts
    34

    Question about May 1992, Problem 12

    Hey all. I'm having a bit of a problem. In Dr. Ostazewski's manual, it's number 13 in practice exam 5. I'm confused about the area of integration. Since y >= x, I thought the area should have been x: (0 to w), y: (x to 1), and for the second part x: (w to sqrt w), y: (x to w/x)? In simpler terms, I thought the shaded region should be to the upper left of the line y = x instead of to the lower right. I don't get it. I would be more than grateful if someone could help me out. Thanks very much all.

  2. #2
    Author, Instuctor and Seminar Provider krzysio's Avatar
    Join Date
    Mar 2005
    Location
    Illinois, USA
    Posts
    1,813

    Question about May 1992, Problem 12

    Dear Robertr24:

    I do not know which edition of my manual you have: first or second edition, but
    I think this is probably a typo that I have corrected in one of these posted errata:

    First edition:
    http://www.math.ilstu.edu/krzysio/P-Manual-Errata.pdf

    Second edition:
    http://www.math.ilstu.edu/krzysio/P-...dEd-Errata.pdf

    I hope this helps. If it does not, please reply, or send me an e-mail.

    Yours most sincerely,
    Krzys' Ostaszewski


    Quote Originally Posted by robertr24
    Hey all. I'm having a bit of a problem. In Dr. Ostazewski's manual, it's number 13 in practice exam 5. I'm confused about the area of integration. Since y >= x, I thought the area should have been x: (0 to w), y: (x to 1), and for the second part x: (w to sqrt w), y: (x to w/x)? In simpler terms, I thought the shaded region should be to the upper left of the line y = x instead of to the lower right. I don't get it. I would be more than grateful if someone could help me out. Thanks very much all.
    Want to know how to pass actuarial exams? Go to: smartURL.it/pass

  3. #3
    Actuary.com - Level II Poster
    Join Date
    Mar 2005
    Location
    United States
    Posts
    34
    Thanks. That clears things up a bit. However, I'm still confused about the actual integration. In the manual you have x:={0 to sqrt w}, y:={0 to x} for the first part, x:={sqrt w to 1}, y:={0 to x/w} for the second part. Doesn't this correspond to the area below the line y = x?

  4. #4
    Author, Instuctor and Seminar Provider krzysio's Avatar
    Join Date
    Mar 2005
    Location
    Illinois, USA
    Posts
    1,813

    November 1992, Problem No. 12

    The intersection of the line y = x and the hyperbola xy = w is at the point
    ( w^0.5, w^.05). First part is the integral over the shaded region between
    the origin and the line y = w^.05, the second one is above that line
    and still under the hyperbola. I still had typos in this solution, so I updated
    the errata, and you can download corrected versions here:
    http://www.math.ilstu.edu/krzysio/P-...dEd-Errata.pdf
    http://www.math.ilstu.edu/krzysio/P-Manual-Errata.pdf

    Yours,
    Krzys'


    In the first part, we have

    Quote Originally Posted by robertr24
    Thanks. That clears things up a bit. However, I'm still confused about the actual integration. In the manual you have x:={0 to sqrt w}, y:={0 to x} for the first part, x:={sqrt w to 1}, y:={0 to x/w} for the second part. Doesn't this correspond to the area below the line y = x?
    Want to know how to pass actuarial exams? Go to: smartURL.it/pass

  5. #5
    Actuary.com - Level II Poster
    Join Date
    Mar 2005
    Location
    United States
    Posts
    34
    Thanks very much. I knew something was wrong there. It makes much more sense with the dx's and dy's interchanged. Sorry to drive you crazy. I will definitely look through ALL the errata before I post questions from now on.

  6. #6
    Author, Instuctor and Seminar Provider krzysio's Avatar
    Join Date
    Mar 2005
    Location
    Illinois, USA
    Posts
    1,813

    Drive crazy? Not at all.

    Dear Robert24:

    Unfortunately, errors and typos still show up in my manuals, despite my best efforts.
    So, I view your inquiry as a very nice gesture, helping me correct those errors. I appreciate it very much.

    Yours very truly,
    Krzys' Ostaszewski

    Quote Originally Posted by robertr24
    Thanks very much. I knew something was wrong there. It makes much more sense with the dx's and dy's interchanged. Sorry to drive you crazy. I will definitely look through ALL the errata before I post questions from now on.
    Want to know how to pass actuarial exams? Go to: smartURL.it/pass

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Question on Krzys' problem 35
    By Martin Birkenheier in forum SOA Exam FM / CAS Exam 2 - Financial Mathematics - with practice exam problems
    Replies: 1
    Last Post: May 19th 2006, 05:44 AM
  2. question on Exam P problem
    By SCIGEEK in forum Actuarial Exams - General Discussion
    Replies: 5
    Last Post: February 15th 2006, 09:54 AM
  3. Problem question
    By Marco in forum Actuarial Exams - General Discussion
    Replies: 1
    Last Post: October 10th 2005, 02:00 PM
  4. Exam P Question - integration problem
    By AlG in forum SOA Exam P / CAS Exam 1 - Probability - with practice exam problems
    Replies: 0
    Last Post: August 11th 2005, 12:05 PM
  5. ACTEX P Chapter 3 problem set question
    By Canadian in forum SOA Exam P / CAS Exam 1 - Probability - with practice exam problems
    Replies: 2
    Last Post: July 18th 2005, 01:32 PM

Posting Permissions

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