Read the bounce heights from the bar graph:

• 1st bounce: $13$ inches
• 2nd bounce: $3$ inches
• 3rd bounce: $6$ inches
• 4th bounce: $1$ inch

$\text{Mean} = \frac{13 + 3 + 6 + 1}{4} = \frac{23}{4} = 5.75 \text{ inches}$