The distance (in km) of 40 engineers from their residence to their place of work were found as follows: 5, 3, 10, 20, 25, 11, 13, 7, 12, 3, 11, 9, 10, 12, 17, 18, 11, 3, 2, 17, 16, 27, 9, 7, 8, 3, 5, 12, 15, 18, 3, 12, 14, 29, 6, 15, 15, 7, 6, 12. Construct a grouped frequency distribution table with class size 5 for the data given above taking the first interval as 0-5 (5 not included). What main features do you observe from this tabular representation?

First, we arrange the data in ascending order:
3, 3, 3, 5, 5, 6, 6, 7, 7, 7, 9, 9, 10, 10, 11, 11, 11, 12, 12, 12, 12, 13, 14, 15, 15, 15, 16, 17, 17, 18, 18, 20, 25, 27, 29

The class intervals with a class size of 5 are:
0-5, 5-10, 10-15, 15-20, 20-25, 25-30

Now, we count the frequency of each class interval:
0-5: 4
5-10: 8
10-15: 11
15-20: 8
20-25: 1
25-30: 3

Grouped Frequency Distribution Table:

Main Features Observed:

The table shows that the majority of engineers travel a distance between 10 km and 15 km to reach their workplace. There is a fairly symmetrical distribution around the 10-15 km range, suggesting a central tendency in the travel distance. The number of engineers who travel longer distances (25 km and above) is relatively low compared to the shorter distances.