【正确答案】(1)股票A、B的期望收益分别为:

=0.1×0.06+0.6×0.07+0.3×0.1 l=8.1%

=0.1×(一0.02)+0.6×0.13+0.3×0.33=15.7%
(2)股票A、B的标准差分别为:
σ
A2=0.10×(0.06一0.081)
2+0.60×(0.07—0.081)
2+0.30×(0.11—0.081)
2 =0.00037
σ
B2=0.10×(一0.2—0.1570)
2+0.60×(0.13—0.1570)
2+0.30×(0.33—0.1570)
2 =0.02216
