Stem-leaf is another visualization you need to get yourself acquainted with. Again this section is different to pervious section in the reading of data part. Once you get a hold of that, skill of going about solving problem remains unchanged.
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The stem leaf below represents age of people in a sample.
Calculate i) mean, ii) mode, iii) median, iv) lower quartile, v) upper quartile, vi) interquartile range, vii) range