Draw a histogram of the data.

The given data is:

To draw a histogram, plot the distance intervals on the x-axis and the frequency on the y-axis. Each bar should correspond to a class interval, with its height representing the frequency. The bars should be adjacent.

• X-axis (Distance in km): Intervals $0-5$, $5-10$, $10-15$, $15-20$, $20-25$.
• Y-axis (Frequency): Values from 0 to 8.
• Bars:
  • For $0 < x \le 5$: Height = 3
  • For $5 < x \le 10$: Height = 6
  • For $10 < x \le 15$: Height = 8
  • For $15 < x \le 20$: Height = 7
  • For $20 < x \le 25$: Height = 1

To draw a line graph (frequency polygon), first find the midpoint of each class interval. Then plot these midpoints against their corresponding frequencies and connect the points with straight lines. To close the polygon, add midpoints for the classes before and after with a frequency of 0.

• Midpoints ($m$):

  • $0 < x \le 5$: $m = \frac{0+5}{2} = 2.5$
  • $5 < x \le 10$: $m = \frac{5+10}{2} = 7.5$
  • $10 < x \le 15$: $m = \frac{10+15}{2} = 12.5$
  • $15 < x \le 20$: $m = \frac{15+20}{2} = 17.5$
  • $20 < x \le 25$: $m = \frac{20+25}{2} = 22.5$

• Points to plot (midpoint, frequency):

  • $(2.5, 3)$
  • $(7.5, 6)$
  • $(12.5, 8)$
  • $(17.5, 7)$
  • $(22.5, 1)$

• To close the polygon:

  • Add $( -2.5, 0)$ for the class before ($-5 < x \le 0$).
  • Add $(27.5, 0)$ for the class after ($25 < x \le 30$).

The modal group is the class interval with the highest frequency.
From the table, the highest frequency is 8, which corresponds to the distance group $10 < x \le 15$.
The modal group is $\boxed{\text{10 < x \le 15}}$.

The data ranges from 0 km to 25 km. The frequencies are concentrated in the middle intervals, particularly between 10 km and 15 km, which has the highest frequency. The frequencies decrease towards the extreme ends (0-5 km and 20-25 km), indicating that very short and very long trips are less common. The data shows a moderate spread, with most trips falling within a reasonable range around the average.