There are 14 total numbers.
Make a list of the 7 lowest numbers:
-5, -4, -3, -2, -1, 0 , 1
The first quartile is the middle value of the lower half of numbers
Since there are 7 numbers ( odd number), the middle value is the middle number, which is -2
Now make a list of the 7 highest numbers:
2, 3 , 4, 5 , 7, 7, 7
The 3rd quartile is the middle value of the higher half of numbers.
Again because there are 7 numbers ( odd number), the middle value is the middle number, which would be 5.
First quartile = -2
Third quartile = 5