30.设 approx N((mu )_(1),({sigma )_(1)}^2) backsim N((M)_(2),({sigma )_(2)}^2) 从总体X与总体Y各取容量分别为7和5的-|||-样本,具体如下:-|||-X: 81 165 97 134 92 87 14-|||-Y:102 86 98 109 92-|||-设两样本独立,取 alpha =0.05,-|||-(1)检验假设 _(0):({sigma )_(1)}^2=10({C)_(2)}^2 v (s)_(1):({sigma )_(1)}^2neq 10({C)_(2)}^2; (此处的倍数10是由工程师根-|||-据实际情况提出的.)-|||-(2)利用(1)的结果,检验 _(0):(mu )_(1)-(mu )_(2)=10 v (H)_(1):(mu )_(1)-(mu )_(2)neq 10.