We routinely use the normal quantile plot to check for normality. One can also use a chi-squared test. For that, we have to group the data into bins, converting numerical data into categorical data...

We routinely use the normal quantile plot to check for normality. One can also use a chi-squared test. For that, we have to group the data into bins, converting numerical data into categorical data

The following figure shows the normal quantile plot of daily stock returns in 2010 on the value-weighted total U.S. market index.

The following table counts the number of returns falling into 8 intervals. The table includes the count expected under the assumption that these data are normally distributed, using the sample mean
 =
.