Analyse the MASS survey data sets in package, complete the following requirements:
1. List the meaning of the data set, the meaning of each field expression,
2. Use the basic command function exploration data set, view the types and properties of each field,
3. Record deleted, containing a missing value
4. Without the return of random sampling, sample content is 20% of the total sample size, and to save sample set for subset1,
5. According to the W.H nd field stratified sampling (the proportion of each layer sample drawn), total sample drawn for 25% of the total sample set,
Will draw sample set is saved as a subset2,
6. Statistics respectively concentrated type field sample size for factor,
7. Calculate the average age of the different gender, height,
8. Draw the Smoke of the bar graph of different gender, contains the title, the name of axis, the color of the legend, set beautiful
And font,
9. On a drawing area, drawing different smoke case, the changes of the age and height map, the requirement phase add
Should be the object,