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

30 August 2014

Adjusted index: Rune Index Adjustment date: 30 August 2014 Affected templates: Template:GE Rune Index and Template:GE Rune Index/Diff Added item(s): Steam rune, Mist rune, Dust rune, Smoke rune, Mud rune, Lava rune Removed item(s): None Items before adjustment: 15 Items after adjustment: 21 Divisor before adjustment: 15.5671 Divisor after adjustment: 21.2740 Item Base date Base price Price on adjustment date Comments Air rune 15 December 2007 11 19 Unchanged Mind rune 10 6 Water rune 15 26 Earth rune 11 14 Fire rune 10 22 Body rune 9 8 Cosmic rune 140 245 Chaos rune 102 41 Nature rune 258 263 Law rune 304 281 Death rune 299 163 Astral rune 132 245 Blood rune 336 261 Soul rune 335 153 Armadyl rune 14 October 2011 1,817 389 Steam rune – – 37 Added item Mist rune 348 Dust rune 66 Smoke rune 314 Mud rune 775 Lava rune 49 Calculations From the old divisor obtained from the templates: ${div}_{\text{old}} = 15.5671$ 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: $\begin{align} \sum \left ( \frac{p}{q} \right )_{\text{old}} & = \text{sum of ratios prior to change} \\ & = \frac{19}{11} + \frac{6}{10} + \frac{26}{15} + \dots + \frac{153}{335} + \frac{389}{1,817} \\ & = 16.36670735 \text{ (up to 8 d.p.)} \end{align}$ And also: $\begin{align} \sum \left ( \frac{p}{q} \right )_{\text{new}} & = \text{sum of ratios prior to change} - \text{sum of removed ratios} + \text{sum of added ratios} \\ & = \sum \left ( \frac{p}{q} \right )_{\text{old}} - \text{sum of removed ratios} + \text{number of added items} \\ & = 16.36670735 - 0 + 6 \\ & = 22.36670735 \text{ (up to 8 d.p.)} \end{align}$ Thus, the new divisor is: $\begin{align} {div}_{\text{new}} & = {div}_{\text{old}} \times \frac{\sum \left ( \frac{p}{q} \right )_{\text{new}}}{\sum \left ( \frac{p}{q} \right )_{\text{old}}} \\ & = 15.5671 \times \frac{22.36670735}{16.36670735} \\ & = 21.2740 \text{ (4 d.p.)} \end{align}$