Empty blocks in a table

Hi

We are trying to understand the metric reported by various data dictionary views related to space occupied in the database for a particular table and have couple of questions

SQL> select table_name,last_analyzed from user_tables where table_name='TEST';

TEST                          17-AUG-10

SQL> select table_name,round((blocks*8),2)/1024 ||'MB' "size"
  2  from user_tables
  3  where table_name ='TEST';

TEST                          158.57 MB

SQL> select table_name,round((num_rows*avg_row_len/1024/1024),2)||' MB' " size"
  2  from user_tables
  3  where table_name = 'TEST';


TEST                          6.17 MB


Q # 1 --> Could you please verify if the following analysis is correct

1. The table is highly fragmented (possibly due to high amount of DELETES)