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

**undefined XP**

- 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.