Requesting clarification and steps for the following question.

Question 1: Suppose that you want to randomly draw 20 observations in the range between 100 and 1000. You plan to use Excel to generate this sample.

1. What is the Excel formula/syntax you need to generate this sample?

2. If now, instead of randomly drawing 20 observations between 100 and 1000, you decided to first divide the range (100,1000) into 10 mutually exclusive & collectively exhaustive groups, then randomly draw/generate 2 observations from each of the 10 groups, what is the sampling method?

What's the advantage of this method compared with the method in part i?

3. If now, you decided to first divide the range (100,1000) into 10 mutually exclusive & collectively exhaustive groups, then randomly select 5 groups and then draw/generate 4 observations from each of the 5 groups, what is the sampling method?

What's the advantage/disadvantage of this method compared with the method in part ii?