以下为单因子随机试验结果，三台机器（A，B，C）的结果如下：
A B C
42-3
801
51-2
72-1
640
请问：误差项的平方和等于多少？（）

Contributions to a Roth IRA:I.May be rolled-over from a regular IRA in a nontaxable transaction.II.May be tax deductible.III.Are not taxed when withdrawn if they have been in an established account for at least five years and the taxpayer is at least 591 2 before withdrawals are made.().A、Only statement I is correctB、Only statement II is correctC、Only statement III is correctD、Statements I, II, and III are correct 点击查看答案

自2016年2月1日起，按月纳税的月销售额或营业额不超过（）万元的缴纳义务人，免征教育费附加、地方教育附加、水利建设基金。 点击查看答案