What does it mean when it says summarize the data?

Answer 1

To summarize data, means to write a statement, or few sentences describing the meaning of your data observations.

Depending on the nature of the information, these summary statistics and related sentences may be about the mode(s), median or mean (or more than one of them) as indicators of the central tendency. These should answer questions such as what values are the data most likely to take. Note that "values" need not be numeric. If the variable in question is favourite fruit, the answer may be apples.

Where appropriate, summarising could also include comments on the maximium, minimum and range, or interquartile range as a measure of the spread of the data. Other percentile ranges may be given instead.

Finally, there are other measures such as the standard error, the skewness and, rarely, higher order moments of the distribution which give more detailed information about the spread of the data.