To find the probability that a randomly selected student is in 9th grade and chose pizza, we need to determine the number of 9th graders who chose pizza, and then divide that by the total number of surveyed students.
From the table, the number of 9th graders who chose pizza is 30. The total number of students surveyed is 450.
Now, we can calculate the probability:
\[ \text{Probability} = \frac{\text{Number of 9th graders who chose pizza}}{\text{Total number of students}} = \frac{30}{450} \]
Now, simplify the fraction:
\[ \frac{30}{450} = \frac{1}{15} \approx 0.0667 \]
To convert this to a percentage, multiply by 100:
\[ 0.0667 \times 100 \approx 6.67% \]
Rounded to the nearest whole percentage, this is approximately 7%.
Thus, the probability that a randomly selected student is in 9th grade and chose pizza is:
7%