What does a normal QQ plot look like?
The normal distribution is symmetric, so it has no skew (the mean is equal to the median).
On a Q-Q plot normally distributed data appears as roughly a straight line (although the ends of the Q-Q plot often start to deviate from the straight line)..
How do you describe a normal quantile plot?
A normal quantile plot (also known as a quantile-quantile plot or QQ plot) is a graphical way of checking whether your data are normally distributed. On one axis, you plot your data, sorted smallest to largest. On the other axis you plot the numbers you would expect to see if your data were normally distributed.
What is a QQ plot?
The quantile-quantile (q-q) plot is a graphical technique for determining if two data sets come from populations with a common distribution. A q-q plot is a plot of the quantiles of the first data set against the quantiles of the second data set. … A 45-degree reference line is also plotted.
What is the difference between PP plot and QQ plot?
A P-P plot compares the empirical cumulative distribution function of a data set with a specified theoretical cumulative distribution function F(·). A Q-Q plot compares the quantiles of a data distribution with the quantiles of a standardized theoretical distribution from a specified family of distributions.