Let X1,X2,⋯,Xn be
independent identically distributed random variable with Sk= X1+ X2+⋯+ Xk
and Sk+=max[0,Sk]. We shall derive formulas for the computation of
E[min1≦k≦nSk+],E[max1≦k≦nSk], and E[min1≦k≦nSk]. The formulas are then
applied to the case of standard normal random variables.