I just did the following question and now I am confused whether my understanding of stratified sampling is incorrect.
An analyst decides to select 5 stocks for his portfolio by placing the ticker symbols for all the stocks of the NYSE in a large bowl. He randomly selects 5 of these stocks. The analyst used:
A) Dual random sampling
B) simple random sampling
C) stratified random sampling
B) is correct.
I re-read the learning objective but I am still unsure about the following: arent the stocks of the NYSE already a stratum of all the stocks globally available? If yes, we would have a stratified sample and the solution would bei c)…
What am i missing here?