A A:n≤300时,按<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20241227/9119959_0.jpg">随机取样 B
B:n>300时,按<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20241227/9119959_0_1.jpg">随机取样 C
C:n>300时,按<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20241227/9119959_0_2.jpg">随机取样 D
D:n>300时,按<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20241227/9119959_0_3.jpg">随机取样 E
E:300≥n>3时,随机取样