You have a cell suspension for which you need to determine the cell concentration.  You have stained your cells with trypan blue, using 20μl of cell suspension and 20μl of trypan blue.  Trypan blue stains dead cells blue, while live cells exclude this dye.

Your counts for each of the outer squares are:

1. Viable: 112; Dead: 26
2. Viable: 100; Dead:22
3. Viable: 109; Dead: 28
4. Viable: 107; Dead: 21

What is the concentration of viable cells in your sample? (You need to answer in standard notation, e.g. 4500 rather than 4.5×10³.)  (You must include units in your answer.)