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Succeed with maths: part 2

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# 1.2 Is the mean the best average to use?

As you learned earlier one of the advantages of using the mean as an average value is that it takes account of all the values in the data set. However, this also means that if one of the values is much higher or lower than the other values it can greatly affect the mean. The following activities will look at this.

Suppose somebody is planning a visit to Vermont, USA in October and they want an idea of how much rainfall there will be. To do this they consult records from the National Climate Data Center in the USA, and find the following:

Table 2 Precipitation (rainfall) in Vermont for October 2007–2011
Year20072008200920102011
Rainfall, in inches (to 1 d.p.)5.85.24.69.34.5
(Enloe, 2013)

What the person really wants to know though is, is what the typical value for October would be. Let’s start with calculating the mean to find this.

## Activity 2 How wet is it in Vermont in October?

Timing: Allow approximately 5 minutes

Find the mean rainfall in Vermont in October for these five years.