In a research laboratory scientists treated \(6\) mice with lung cancer using natural medicine. Ten days later, they measured the volume of the tumor in each mouse and given the results in the table.
 
Mouse marking \(1\) \(2\) \(3\) \(4\) \(5\) \(6\)
Tumor Volume (\(mm^3\)) 145 149 141 141 138 140
 
Find the mean.
 
Answer:
 
Mean \(=\) \(mm^3\)
 
(Note: Round off the answer to \(1\) decimal place.)