The capital investment cost for a switchgrass-fueled ethanol plant with a capacity of 250,000 gallons per year if $1.4 million. The cost-capcaity factor for this particular plant technology is 0.59 for capacities ranging from 200,000 gallons per year to 500,000 gallons per year. What is the estimated capital investment for a similar ethanol plant with a capacity of 500,000 gallons per year?