Average Price of an Engagement Ring Purchased Online

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A Statistical Study Evaluating the Average Cost
of Engagement Rings Purchased Online

• Presented by BuyDiamondRings.org

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Whats the Average Cost of an Engagement Ring?

• Many sources have reported different numbers,
  ranging from 3,000 to 6,000.
• About.com reports that the average cost is the
  range of 3,500 to 4,000 (link)
• Learnvest.com reports that the average engagement
  ring in 2009 sold for 3,150 (link).
• TheKnot.com reports that the average cost of an
  engagement ring in 2010 was 5,392 (link).

3
What about online, specifically?

• The Wall Street Journal reported in 2006 that
  5,600 was the average cost for an engagement
  ring purchased on the net (link).
• I focused on online engagement ring sales for my
  study.
• I took a sample of 829 engagement rings sold
  online in late 2010/early 2011 and analyzed the
  cost data.

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Heres what I found

• Most expensive ring 86,829.
• Lease expensive ring 698 .
• Mean 8,613.26.
• Median 6,071.00.
• Mode 3,379.00.
• Standard Deviation 8,144.90.
• Skew 3.07
• The skew is important notice it on the graph
  on the next slide.

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The results

• As you can see, there were two things that stood
  out about the histogram.
• 1 The skewness. As reported a few slides back,
  there is a strong skew value of 3.07
• 2 The outliers. There were numerous outlies on
  the upper end of the distribution.
• What happens when I remove the outliers?

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Results with Outliers Removed

• Mean 7,696.63.
• Median 5,969.00.
• Standard Deviation 5,707.24.
• Skew 1.36
• The mean changed drastically, but the median was
  almost unchanged. This is typical when there are
  so many outliers and a strong skewness. Heres
  the graph without the outliers

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Still skewed, but better

• Even after removing the outliers, the
  distribution is still skewed.
• Given the skew and the outliers, the median is a
  better measure of the average cost of an
  engagement ring purchased online.
• In this study, the two medians were 6,071 and
  5,969. Averaging these two medians out gives
  6,020, almost exactly 6,000.
• Using these results, I would infer that the
  average price of an engagement ring purchased
  online is 6,000.

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• This was a presentation by BuyDiamondRings.org.
• Data was provided by Blue Nile.
• If you are in the market for an engagement
  yourself, please read our engagement rings guide.