[Step 1] Put data in order least to greatest
-> Data is already in order, fantastic!
[Step 2] Find the medium of all the data
-> We will find the middle value
-> See attached, in black
-> The value is 7.5
[Step 3] Find the medium of our halves
-> We will find the middle value of each of the halves
-> See attached, in white
-> For this, the value of the first quartile it is 3.5
-> For the, the value of the third quartile it is 9
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
