Exercise

# 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.

Instructions 1/3

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#### Question

Which of the below sentences about the Q-Q plot is true?

##### Possible Answers

- A point on the plot corresponds to one of the quantiles of the second distribution plotted against the same quantile of the first distribution.
- A Q-Q plot is a graphical method for comparing two probability distributions by plotting their quantiles against each other.
- If the two distributions being compared are similar, the points will approximately lie on the line.
- All of the above answers are true.