To make predictions about financial markets it is important to determine the distributional form of average daily returns. Of course, in practice you should use as much data as possible to make this decision. Here we will use daily returns for 128 days of trading of May 1, 2017, to October 30, 2017, to find out if the average daily returns are normally distributed. This data can be found in the Excel file DJIA.xlsx.

a. Using α = 0.01, perform a chi-square test to determine if the data follow a normal probability distribution.

b. Determine the p-value for the chi-square test statistic using Excel and interpret its meaning.