\(\sqrt{27} , \sqrt{48} , \sqrt{75}\) ......A.P.
\(3\sqrt{3} , 4\sqrt{3} , 5\sqrt{3}\) ......A.P.
First term : \(a=3\sqrt{3}\)
Common Difference : \(d=a_{2}-a_{1}\)
\(d=4\sqrt{3}-3\sqrt{3}\)
\(d=\sqrt{3}\)
n th term of an A.P. is ,
\(a_{n}=a+(n-1)d\)
4th term of A.P. is
\(a_{4}=a+3d\)
Substitute the values of a and d
\(a_{4}=(3\sqrt{3})+3(\sqrt{3})\)
\(a_{4}=6\sqrt{3}\)