I need help with this 5th Grade Math

What situation is an example of an observational study

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)