Michael is using earned value analysis for his project on airline customer satisfaction. Based on information about the project after nine months, what is the schedule performance index (SPI) and what does it mean? Duration: 1 year Budget: $500,000 Actualcost at Month 9: $390,000 (For Ref Only, Question #: PM-02561) Group of answer choices 0.90; work is behind schedule 1.11; work is ahead of schedule 1.07; work is ahead of schedule 0.93; work is behind schedule.