This is an easy set of questions to get you started with Stata. It uses an old data set on cars from Consumer Reports that is built into Stata. To
This is an easy set of questions to get you started with Stata. It uses an old data set on cars from Consumer Reports that is built into Stata. To load the data into Stata, enter the following command in Stata’s command line: sysuse auto. To see what is in this data set, you can enter the Stata command describe. a) Calculate the mean price of the automobiles in the data set. You can do this by writing summarize price in the command line. was the mean price of automobiles in 1978? b) Calculate the median price of the automobiles in the data set. You can do this by writing summarize price, detail in the command line. was the median price of automobiles in 1978? does the difference between the mean and median price indicate about the shape of the distribution for the price? c) Make a histogram of the price of cars. You can do this by using the command histogram price. shape does the histogram take? (Is it symmetric? Skewed?) Does the shape of the histogram coincide with what you guessed in part (b)? d) Run the Stata command by foreign: summarize price and comment on the average price of cars for foreign versus domestic. e) You can also obtain subgroup analysis using an if statement. Run the two commands summarize mpg if foreign==0 and summarize mpg if foreign==1, and comment on differences in average mpg between domestic and foreign cars. f) The command histogram mpg,by(foreign) creates side by side histograms. Comment on the difference in distributions of mpg for domestic and foreign cars. g) Make a scatter plot of the variables weight and length. You can use the command, scatter weight length. Does there appear to be any association between the variables? Also compute the correlation and covariance between weight and length. h) Using the standard deviations of weight and length, show how the covariance divided by the standard deviations equals the correlation value. Use the following data set listed below. 4099 4749 3799 4816 7827 5788 4453 5189 10372 4082 11385 14500 15906 3299 5705 4504 5104 3667 3955 3984 4010 5886 6342 4389 4187 11497 13594 13466 3829 5379 6165 4516 6303 3291 8814 5172 4733 4890 4181 4195 10371 4647 4425 4482 6486 4060 5798 4934 5222 4723 4424 4172 9690 6295 9735 6229 4589 5079 8129 4296 5799 4499 3995 12990 3895 3798 5899 3748 5719 7140 5397 4697 6850 11995
