Instruction: Explain how to use the 'summary' function in R and provide an example using any dataset of your choice. Describe what statistical information the function returns by default.
Context: This question evaluates the candidate's familiarity with R's built-in functions for descriptive statistics. It checks the candidate's ability to leverage R's capabilities to summarize key statistical information about data, which is crucial for any data analysis task.
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Firstly, to utilize the 'summary' function in R, you simply call summary() and pass the data object as an argument. This could be a vector, data frame, or even a more complex object like a model. By default, for numerical data, the function returns the minimum, first quartile, median, mean, third quartile, and maximum values. For factors, it returns a frequency count of each level.
For instance, let's consider a simple example using the mtcars dataset, which is readily available in R. This dataset contains various characteristics of 32 automobiles. To get a statistical summary of this dataset, you would execute the following code: R summary(mtcars) This command yields a quick statistical summary for each variable in the dataset. For numerical...