Monthly Archives: October 2011

Presidential Elections and Statistical Inference

We use an example of presidential elections to illustrate the reasoning process of statistical inference. The current holder of a political office is called an incumbent. Does being an incumbent give an edge for reelection? The answer seems to be … Continue reading

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A Case of Restaurant Arson and the Reasoning of Statistical Inference

I know of a case of a restaruant owner who was convicted for burning down his restaurant for the purpose of collecting insurance money. It turns out that this case is a good example for introducing the reasoning process of … Continue reading

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Rolling Dice to Buy Gas

The price of gas you pay at the pump is influenced by many factors. One such factor is the price of crude oil in the international petroleum market, which can be highly dependent on global macroeconomic conditions. Why don’t we … Continue reading

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The Middle 80% Is Not 80th Percentile

A student sent me an email about a practice problem involving finding the middle 80% of a normal distribution. The student was confusing the middle 80% of a bell curve with the 80th percentile. The student then tried to answer … Continue reading

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Coin Tossing and Family Size

If you a toss a coin 9 times, what is the probability of obtaining 8 heads and 1 tail? I just tossed one penny 9 times and the following is the resulting sequence of heads and tails. The above little … Continue reading

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