Role-playing games like Dungeons & Dragons use many different types of dice. One type of die has a tetrahedral (pyramidal)shape with four triangular faces. Each triangular face has a number (1, 2, 3, or 4) next to each of its edges. Because the top ofthis die is not a face but a point, the way to read it is by the number at the bottom of the face that is visible when the diecomes to rest. Suppose that the vitality of a character is determined by rolling this four-sided die twice and adding 2 to the sumof the rolls. The probability model for this is given below.
| Intelligence | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| Probability | 1/16 | 2/16 | 3/16 | 4/16 | 3/16 | 2/16 | 1/16 |
The mean vitality is 7. Jermaine plays this character often. What interval covers (approximately) the middle 68% of average vitality scores for 81 of Jermaine's games? (Round your answers to two decimal places.)