Commodity data detective quiz.
Practice reading dates, averages, indexes, missing values and fair comparisons. Every answer includes a short explanation.
Answers and explanations.
Try the quiz first. Then open any question to check the answer and the reason behind it.
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A price is labelled “monthly average.” What does it describe?
Choices: A group of observations across that month · One live trade right now · A guaranteed price next month
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A group of observations across that month. A monthly average summarizes observations from the named month. It is not live and is not a forecast.
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What should a blank value mean in a dataset?
Choices: The value is missing or unavailable · The value is definitely zero · The price was free
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The value is missing or unavailable. Blank data should not be silently turned into zero. Missing and zero are different facts.
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Why index two series to 100 on the same start date?
Choices: To compare their percentage-like movement · To predict tomorrow · To give them the same physical unit
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To compare their percentage-like movement. Indexing gives each series the same starting point, making relative movement easier to compare.
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Two prices moved together. Does that alone prove one caused the other?
Choices: Yes · No
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No. No. Movement together is a clue to investigate, not proof of cause and effect.
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Which detail belongs next to every quoted price?
Choices: Observation date and unit · A future prediction · A social-media score
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Observation date and unit. The date and unit tell the reader what the number measures and when it was observed.
Learn more about this topic.
- Reading historical price charts: averages, gaps and partial periods.
- Commodity data workbench: compare series on shared dates.
- Data methodology: how each price on this site is sourced.