ShmoopTube

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And here's your shmoop du jour.

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It's three weeks until Christmas, and Santa is going coal shopping.

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The graph below shows local average coal prices (in dollars per pound) over four weeks.

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Based on the graph, what is the expected coal price for week six?

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And here are the potential answers

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Hit pause and try it yourself. Go on.

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Can we read a graph and take its trendline? That's what this question is asking.

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All we need is a ruler.

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Uh, this kind of ruler.

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We can hold it flat against the series of dots here, look down and continue until we

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intersect the vertical line from week 6. If we wanna do this problem in a mathy way,

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we simply observe the increase in price each week.

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Prices have gone up 20 cents a week.

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In week 4, coal is $3.80 so we can predict that in week 5 its 4 bucks and in week 6 which the question is asking,

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it's $4.20. Answer C. Done.

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Wait a second, that's not Santa!

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