\((1)\)已知向量\(\overrightarrow{a} =(-2,3)\)，\(\overrightarrow{b} =(3,m)\)，且\(\overrightarrow{a} ⊥\overrightarrow{b} \)，则\(m=\)______．
\((2)\)设某总体是由编号为\(01,02,...,19,20\)的\(20\)个个体组成，利用下面的随机数表选取\(6\)个个体，选取方法是从随机数表第\(1\)行的第\(3\)列和第\(4\)列数字开始由左到右依次选取两个数字，则选出来的第\(6\)个个体的编号是_________．
\(7816\) \(6572\) \(0802\) \(6316\) \(0702\) \(4369\) \(9728\) \(1198\)
\(3204\) \(9234\) \(4915\) \(8200\) \(3623\) \(4869\) \(6938\) \(7481\)
\((3)\)已知\(α,β∈( \dfrac{3π}{4},π),\sin (α+β)=- \dfrac{3}{5} \)，\(\sin (β- \dfrac{π}{4})= \dfrac{12}{13} \)，则\(\cos (α+ \dfrac{π}{4}) = \)______ ．
\((4)\)函数\(f(x)=\sin x+\cos x,g(x)=\sin x·\cos x+ \dfrac{1}{2} \)，动直线\(x=t,t∈[0,π] \)与\(f(x)\)，\(g(x)\)的图像分别交于点\(P\)，\(Q\)，则\(|PQ|\)的最大值是__________．