Thomas Train has collected the following information over the last six months.
| Month | Units produced | Total costs |
| March | 10,000 | $25,600 |
| April | 12,000 | 26,200 |
| May | 19,400 | 27,600 |
| June | 13,000 | 26,450 |
| July | 12,000 | 26,000 |
| August | 15,000 | 26,500 |
Using the high-low method, what is the variable cost per unit?
