Remarks:
1. Do not remove the missing value before export the “Clean” data, just change the nvalid categories/values for the categorical variables to NA. And also treatment for the outlier is needed but not delete the missing value in continuous/numeric variables.
2. Missing value can be cleaned after exporting the “Clean” data and before the PCA.
3. 5 pages answer in report style, “Clean data” file and R script written is needed for the assigment.
4. Exempler is provided as reference
5. i have already prepared the sample of 500 observations(mydata.csv), so can skip the part in preparing a sub-sample that is unique to my student number
