RuneScape:Grand Exchange Market Watch/Adjustments (30 December 2014)

30 December 2014

Adjusted index: Discontinued Rare Index Adjustment date: 30 December 2014 Affected templates: Template:GE Discontinued Rare Index and Template:GE Discontinued Rare Index/Diff Added item(s): Rubber turkey, Off-hand rubber turkey, Christmas scythe, Holly wreath Removed item(s): None Items before adjustment: 20 Items after adjustment: 24 Divisor before adjustment: 15.3476 Divisor after adjustment: 15.6373 Item Base date Base price Price on adjustment date Comments Christmas cracker 31 December 2008 688,800,000 2,147,483,644 Unchanged Blue partyhat 340,100,000 2,147,483,647 Green partyhat 114,800,000 1,452,340,733 Purple partyhat 83,100,000 1,233,390,908 Red partyhat 129,400,000 1,738,594,833 White partyhat 183,300,000 2,147,483,644 Yellow partyhat 96,300,000 1,314,553,072 Pumpkin 5,300,000 149,804,919 Easter egg 4,300,000 49,183,614 Blue h'ween mask 12,800,000 101,362,653 Green h'ween mask 10,600,000 82,685,014 Red h'ween mask 17,300,000 132,872,973 Santa hat 14,800,000 115,823,577 Disk of returning 4,700,000 200,971,362 Half full wine jug 31,100,000 348,603,157 Fish mask 29 September 2012 4,555,462 601,926 Christmas tree hat 20 January 2013 2,295,576 12,651,188 Crown of Seasons 23 July 2013 8,307,542 4,044,842 Black Santa hat 20 January 2013 222,967,707 340,890,058 Cloak of Seasons 19 June 2014 7,614,236 27,631,528 Rubber turkey – – 4,140,748 Added item Off-hand rubber turkey 3,590,829 Christmas scythe 72,191,580 Holly wreath 372,492,991 Calculations From the old divisor obtained from the templates: ${div}_{\text{old}} = 15.3476$ We need to calculate a new divisor: ${div}_{\text{new}} = {div}_{\text{old}} \times \frac{\sum \left ( \frac{p}{q} \right )_{\text{new}}}{\sum \left ( \frac{p}{q} \right )_{\text{old}}}$ To calculate the new divisor, we need to find: $\begin{align} \sum \left ( \frac{p}{q} \right )_{\text{old}} & = \text{sum of ratios prior to change} \\ & = \frac{2,147,483,644}{688,800,000} + \frac{2,147,483,647}{340,100,000} + \frac{1,452,340,733}{114,800,000} + \dots + \frac{340,890,058}{222,967,707} + \frac{27,631,528}{7,614,236} \\ & = 211.91329563 \text{ (up to 8 d.p.)} \end{align}$ And also: $\begin{align} \sum \left ( \frac{p}{q} \right )_{\text{new}} & = \text{sum of ratios prior to change} - \text{sum of removed ratios} + \text{sum of added ratios} \\ & = \sum \left ( \frac{p}{q} \right )_{\text{old}} - \text{sum of removed ratios} + \text{number of added items} \\ & = 211.91329563 - 0 + 4 \\ & = 215.91329563 \text{ (up to 8 d.p.)} \end{align}$ Thus, the new divisor is: $\begin{align} {div}_{\text{new}} & = {div}_{\text{old}} \times \frac{\sum \left ( \frac{p}{q} \right )_{\text{new}}}{\sum \left ( \frac{p}{q} \right )_{\text{old}}} \\ & = 15.3476 \times \frac{215.91329563}{211.91329563} \\ & = 15.6373 \text{ (4 d.p.)} \end{align}$