The table shows the distribution of the lengths of 20 iron rods measured in metres :

Length (m)	1.0 - 1.1	1.2 - 1.3	1.4 - 1.5	1.6 - 1.7	1.8 - 1.9
Frequency	2	3	8	5	2

Using an assumed mean of 1.45, calculate the mean of the distribution.