[天と地の守り人] [Vạn cổ tối cưỠng tông] [��D��8�] [tư+duy+mở] [hạn 33 tuổi năm 2025] [lại thằng nhóc emilthằng] [ John J. Murphy] [Kỹ năng] [David, the promoter of an outdoor concert, expects a net profit of $100,000, unless it rains, which would reduce the net profit to $40,000. The probability of rain is 0.20. For a premium of $29,000 David can purchase insurance coverage that would pay him $100,000 in case of rain. Find the expe] [sức báºt sau khá»§ng hoảng]