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The Log Index is made up of a weighted average of all of the current logs listed in the Market Watch, with the starting date of this average on 19 December 2007, at an index of 100. The overall rising and falling of log prices is reflected in this index.

While specialised for just watching log prices, it is set up and adjusted in a manner similar to the Common Trade Index, and the divisor may be adjusted to include new logs added by Jagex (see the FAQ for more information).

As of today, this index is 715.52 Down -0.60

Historical chart

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Summary

Any suggested changes to this index should be added to the talk page.

  • Start date: 19 December 2007 (at index of 100)
  • Index today: 715.52
  • Change today: Down -0.60
  • Number of items: 11 (last adjusted on 8 November 2013)
  • Index divisor: 10.3117 (last adjusted on 8 November 2013)

List of items

This is the current list of items included in this index:

Icon Item Price Direction Low Alch High Alch Limit Members Details Last updated
Achey tree logsAchey tree logs1,058
Unchg
1225,000P2P iconview3 hours ago
Arctic pine logsArctic pine logs345
Unchg
142125,000P2P iconview3 hours ago
Elder logsElder logs9,515
Up
19228825,000P2P iconview2 hours ago
LogsLogs307
DownDown
1225,000F2P iconview2 hours ago
Magic logsMagic logs379
Down
12819225,000F2P iconview2 hours ago
Mahogany logsMahogany logs285
Down
203025,000F2P iconview2 hours ago
Maple logsMaple logs98
UpUp
324825,000F2P iconview2 hours ago
Oak logsOak logs398
Up
81225,000F2P iconview111 minutes ago
Teak logsTeak logs95
UpUpUp
121825,000F2P iconview39 minutes ago
Willow logsWillow logs180
DownDown
162425,000F2P iconview20 minutes ago
Yew logsYew logs170
Unchg
649625,000F2P iconview16 minutes ago


Adjustments

8 November 2013
Item Base date Base price Price on adjustment date Comments
Logs 19 December 2007 34 28 Unchanged
Achey tree logs 40 39
Oak logs 18 12
Willow logs 22 20
Teak logs 136 71
Maple logs 46 30
Mahogany logs 173 392
Arctic pine logs 855 57
Yew logs 413 526
Magic logs 1,221 1,646
Elder logs 3,952 Added item

Calculations

From the old divisor obtained from the templates:

$ {div}_{\text{old}} = 10.0000 $


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{280}{34} + \frac{399}{40} + \frac{123}{18} + \dots + \frac{1,646}{1,221} \\ & = 32.08119681 \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} \\ & = 32.08119681 - 0 + 1 \\ & = 33.08119681 \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}}} \\ & = 10.0000 \times \frac{33.08119681}{32.08119681} \\ & = 10.3117 \text{ (4 d.p.)} \end{align} $
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