I need help to find the Awnser to this

Which situation is an example of an observational study?

Nour and rana are shopping for a christmas tree. they are deciding between 2 22 different types of trees (real and fake) and 4 44 colors for the ornaments (white, silver, gold, and purple). they each created a display to represent the sample space of randomly picking a type of tree and a color for the ornaments. whose display correctly represents the sample space?

What is the following sum in simplest form? square root 8 + 3 square root 2 + square root 32