4. (Computer Exercise) In this exercise, we study the effect of educational attainment on the time spent sleeping per week using the data in PS2 Q4.dta, which contains observations for 676 individuals. Consider the simple regression model: sleep=0+1educ+u, where sleep is minutes spent sleeping at night per week and educ is years of schooling. (a) Find the sample mean and standard deviation of sleep and educ: (b) Draw a scatter plot of sleep versus educ. Do you observe a positiveegativeo correlation between these two variables? (c) Run the regression of sleep on educ (with an intercept). Write down the estimated equation together with the sample size and R2. (d) Interpret the estimated coefficient on educ: (e) Draw a scatter plot of sleep against educ with the fitted regression line (based on the regression in (c)) displayed in the same figure. 4. (Computer Exercise) In this exercise, we study the effect of educational attainment on the time spent sleeping per week using the data in PS2 Q4.dta, which contains observations for 676 individuals. Consider the simple regression model: sleep=0+1educ+u, where sleep is minutes spent sleeping at night per week and educ is years of schooling. (a) Find the sample mean and standard deviation of sleep and educ: (b) Draw a scatter plot of sleep versus educ. Do you observe a positiveegativeo correlation between these two variables? (c) Run the regression of sleep on educ (with an intercept). Write down the estimated equation together with the sample size and R2. (d) Interpret the estimated coefficient on educ: (e) Draw a scatter plot of sleep against educ with the fitted regression line (based on the regression in (c)) displayed in the same figure