2015 Spring #21

carrots

Hello,

I don't think I really understand the solution for a) in the examiner's report. The solution doesn't go through the same 7 steps that we discuss in the the wiki page or in the source material, it uses average untrended severity triangle and then just jumps to calculate the ultimate.

Is that a quicker way to do the disposal rate method and does it work in any situation?

Thanks!

Graham

The examiner's report solutions sometimes take shortcuts or apply the methods slightly differently from the method given in the source text.

You can still solve this problem using the steps in the wiki (see below) and that's how I would recommend doing it. If you're very proficient in applying the disposal rate method, you may be able to take shortcuts but in general it's better to use the standard method because it's easy to make mistakes when trying to cut corners.

The only slight difference is how you make your selections for disposal rates in step 2a, and for severity in step 3a. In each case, you select the latest diagonal instead of an average. These values are shown highlighted in red in the solution below.

• The final answer for AY 2014 is 2,506 (see below).
• The final answer for AY 2013 is (21 x 5,000 x 1.04) + 3,000,000 = 3,109,200.

The calculations shown below are the same as in the examiner's report but they are organized differently so at first glance, it does not look the same. The final answers are the same however.

Here is step 2:

Here is step 3: