
【解答】解:(1)(-4)×3+(-2)×4+0×4+1×8+2×6+3×5,
=-12-8+0+8+12+15,
=-20+35,
=15克,
15÷30=0.5克,
∴这批样品的平均质量比每袋的标准质量多,多0.5克;
(2)30×100+15=3015(克).

【解答】解:(1)(-4)×3+(-2)×4+0×4+1×8+2×6+3×5,
=-12-8+0+8+12+15,
=-20+35,
=15克,
15÷30=0.5克,
∴这批样品的平均质量比每袋的标准质量多,多0.5克;
(2)30×100+15=3015(克).