Q-Q plot
During the interview, you can use a Q-Q plot to support the result of the Shapiro-Wilk test.
A Q-Q plot that compares a certain sample data against the values of a normal distribution helps to assess the normality of the sample visually.
Recall that:
qqplot(x, y)
- produces a Q-Q plot of two datasets,qqnorm(x)
- produces a Q-Q plot against normal distribution.
The line added by qqline(x)
is by default normal.
The cats
dataset from the MASS package is available for this exercise.
This exercise is part of the course
Practicing Statistics Interview Questions in R
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