Chloe$$s Cafe bakes croissants that it sells to local restaurants and grocery stores. The average costs to bake the croissants are $$0\mathrm{.}45$ for $2,100$ and $$0\mathrm{.}40$ for $4,200.$

Required:

If the total cost function for croissants is linear, what will be the average cost to bake $3,400?($Do not round intermediate calculations. Round your final answer to $4$ decimal places.$)$