Goal Seek didn’t find model solution. Why?

Discussion in 'CP2' started by N_Exam, Jul 20, 2022.

  1. N_Exam

    N_Exam Very Active Member

    Hi Tutors and Forum Members,

    I have done the 2019 Sept Paper 2 Exam. However, I couldn't find the same Goal Seek’ed figure as in the examiner's solution. I have checked and my Excel formula and resulting figures in the tab are the same as the examiner’s solution as is my Goal Seek method (what to put into the seek’s input box).

    The Exam's Goal Seek question asks us to find a figure (cost of a parcel delivery) such that all simulations meet a target profit amount. The model answer is 2.3. In fact, any figure between 0 and 2.3 is correct as it will achieve the target profit for all simulations.
    However, my Goal Seek’ed figure found 1.8. This is correct but not sure why I didn’t find model solution of 2.3? In fact, I re-did the Goal Seek on the examiners solution and this time it came out with 1.44, again its correct but not the original examiners solution.

    Any idea what I'm doing wrong? and What's going on?

    Thank You!
     
  2. Lucy England

    Lucy England Member

    Hi, I haven't looked at this particular paper in a while but I do remember there being something odd about the Goal Seek in this one! There's a bit in the Examiners' Report that says lots of people didn't get the Goal Seek quite right:

    The majority of students handled the additional scenario correctly, but there were a large number who did not set up the goal seek correctly. This resulted in a single price which ensures all scenarios result in a profit, but not necessarily the maximum price. Students needed to set the goal seek so that the minimum profit was equal to the target profit, rather than finding a price which set the number of scenarios returning target profit to 100, as this condition was met by any price lower than $2.36.

    Not sure if that helps at all??
     
  3. N_Exam

    N_Exam Very Active Member

    Thank you. I've looked this up and yes, seems something odd about Goal Seek.

    In general for the CP2 Exam, will we get one single answer from Goal Seek and not a range (as described in my question) ?
    or is it best we get the Goal Seek'ed answer and then do a data and reasonableness check on it?

    Thanks :)
     
  4. Lucy England

    Lucy England Member

    Yeah, I think generally you'd expect a Goal Seek calculation to be a bit more straightforward than the one in this particular paper, so you'd just get the one result.

    It's a good idea to do reasonableness checks on the results in your spreadsheet (in both papers) and describe them in your audit trail / summary document. As for the data, you'll normally do data checks in Paper 1 anyway so probably nothing else required other than those. In Paper 2 you can usually assume that your data has already been checked (unless the question says otherwise).
     
  5. N_Exam

    N_Exam Very Active Member

    Thank you for answering my question :)
     

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