A survey was conducted to find the preferred type of pet among students, categorized by grade level.
| Dog | Cat | Other | Total | |
|---|---|---|---|---|
| 9th Grade | 20 | 15 | 5 | 40 |
| 10th Grade | 10 | 25 | 15 | 50 |
| 11th Grade | 5 | 5 | 0 | 10 |
| Total | 35 | 45 | 20 | 100 |
If a surveyed student is chosen at random, what is the probability that the student is in 9th grade? (Express your answer as a decimal or fraction, not as a percent.)
