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# Time for action – the stem function in play

The R function `stem` from the `base` package and `stem.leaf.backback` from `aplpack` are fundamental for our purpose to create the stem-and-leaf plots. We will illustrate these two functions for the examples discussed earlier.

1. As mentioned in Example 4.2.1. Octane Rating of Gasoline Blends, first create the `x` vector, `x<-c(12,22,42,13,27,46,25,52)`.
2. Obtain the stem-and-leaf plot with:
```> stem(x)
The decimal point is 1 digit(s) to the right of the |
1 | 23
2 | 257
3 |
4 | 26
5 | 2```

To obtain the median from the stem display we proceed as follows. Remove one point each from either side of the display. First we remove `52` and `12`, and then remove `46` and `13`. The trick is to proceed until we are left with either one point, ...

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