1. Muhammad Tahir collected data on research methodology for his assignment from a sample of 500 respondents out of a total population of 10,000 to generalize the results to the whole population. 2. There are two main types of data: primary data collected directly for the research, and secondary data previously collected by others. Primary data can be collected through surveys, interviews, questionnaires, observation, while secondary data comes from publications, reports, records. 3. Data analysis involves categorizing, ordering, manipulating and summarizing collected data using statistical tools like MS Excel, SPSS, STATA to interpret results and answer research questions.