Lab-session 2: 1. use lab1.dta; change to your preferred working directory and then open a log file for the work session: cd: c:\... log using name.log 2. look at histograms and density plots for all variables in the variable list kdensity y histogram y etc. 3. test all variables of normality, kurtosis and skewness and interprete the results. swilk y sktest y etc. 4. run one-sample ttest for all variables, use null hypotheses of your own choice: ttest y=4 etc. 5. compare the mean and standard deviations of different pairs of variables and interpret the results. ttest x1=x2 sdtest x5=x6 etc. 6. compare the means and standard deviations of sub-groups of variables by using x9 as a treatment variable: ttest x1, by(x9) ttest x1, by(x9) unequal sdtest x5,by(x9) etc.