The table shows the prices (in dollars) of 8 different types of coffee beans at two stores, Store P and Store Q.
Each column shows prices in dollars
| 1 | 2 | 3 | 4 | 5 | 6 | |
|---|---|---|---|---|---|---|
| Store P | 12.50 | 14.00 | 11.80 | 13.20 | 15.00 | 12.90 |
| Store Q | x | 13.50 | 12.00 | 14.00 | 12.80 | 14.20 |
The mean price of coffee beans at Store Q is dollars less than the mean price at Store P. What is the value of ?
