One means by which one can test if two samples are truly from the same population is to compare the empirical distributions obtained from each data set against each other directly; if the two samples are truly from the same distribution, within the limits of experimental error, there should be no signi?cant difference between the two empirical distributions. State an appropriate null hypothesis and the alternative hypothesis and carry out a chi-squared goodness- of-?t test of the empirical distribution of the data for Period I versus that of Period II. State your conclusions clearly.