Solution: It is known that 2/3 2a = 3/4 3b = 4/3 4c,

Let 2a = 3b = 4c=k(k≠0),

Then from 2/3 a = k, a=2/3k,

3/4 is 3b=k, and b=3/4 is 4k.

4c=k，C = 3k，

3/4 k < 4/3k < 2/3 k

Get c < b < a.

That is, a is the largest and c is the smallest.