Explain observation and experimentation with help of an example. What are different sources of secondary data information? (2 Marks)What are the essential differences among nominal, ordinal, interval, and ratio scales? (1.5 Marks)Discuss Sample versus Census. Describe the differences between a probability sampling and a non-probability sampling. (2 Marks)4.Distinguish between: (1.5 Marks)a.Direct and indirect questionsb.Open ended and closed questionsc.Research, investigative, and measurement questions.FILLER TEXTthis website