Exercise

Shapiro-Wilk test

In this exercise, you will check the normality of data.

Normal data is an underlying assumption for many statistical tests. You need to know how to assess the normality of the data before you run these statistical tests during the interview.

The Shapiro-Wilk test is a popular test for testing normality.

Recall that the log transformation can be used to transform skewed data to approximately conform to normality.

The cats dataset from the MASS package has been preloaded for this exercise. As you may remember, the Hwt variable from this dataset contains data on heart weight in grams.

Instructions 1/4

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  • Plot a histogram of the Hwt variable from cats.
  • Perform the normality test that has the best power for a given significance on the Hwt variable.