I have a VBA program that takes data from similarly formatted
sheets, and present the data onto one sheet, as seen below as
an example

TestNum Value State
1 10 On
4 Off
2 Off
2 8 On
5 On
2 Off

Now I want to be fancy and put a drop-down list on the TestNum
cell so users can choose a certain TestNum and ONLY data for that
TestNum will be show, as seen below if TestNum=2 is chosen

TestNum Value State
2 8 On
5 On
2 Off

However, by default, I want to show ALL test data. Is this easily done
in VBA?