Directions: Following is the table for the results of the heights of some plants which were grown in laboratory and recorded after 30 days (in mm) ||| |---|---| | Height (in mm) | Frequency | | 200 - 210 | 2 | | 210 - 220 | 3 | | 220 - 230 | 1 | | 230 - 240 | 5 | | 240 - 250 | 7 |

What is the class width of the first class interval?