【正确答案】 C

【答案解析】每个投资的期望结果可以用以下的公式计算 期望结果 = (结果值)(该结果的概率) A的期望结果 = (0.3)(-$6,000) + (0.1)(-$10,000) + (0.3)($30,000) + (0.2)($70,000) + (0.1)($100,000) = $26,000 B的期望结果 = (0.2)(-$20,000) + (0.2)(-$10,000) + (0.2)($30,000) +(0.2)($70,000) + (0.2)($100,000) = $34,000 C的期望结果 = (0.3)(-$20,000) + (0.1)(-$10,000) + (0.2)($30,000) + (0.3)($70,000) + (0.1)($100,000) = $30,000