已知\(\{a _{n} \}\)是等差数列，\(\{b _{n} \}\)是各项都为正数的等比数列，\(a _{1} =b _{2} =1\)，再从条件①、条件②、条件③这三个条件中选择两个作为已知．
\((\)Ⅰ\()\)求数列\(\{a _{n} \}\)的通项公式；
\((\)Ⅱ\()\)求数列\(\{b _{n} \}\)的前\(n\)项和．
条件①：\(a _{2} +a _{4} =10\)；条件②：\(b _{2} b _{4} =4\)；条件③：\(b _{4} =a _{5}\)．