One of Cassie Corporation's competitors has learned that Cassie has a total expense per unit of $1.50 at the 15,000 unit level of activity and total expense per unit of $145 at the 20,000 unit level of activity. Assume that the relevant range includes all of the activity levels mentioned in this problem What would be the competitor's prediction of total expected costs at 18,000 units? (Round your Intermediate calculations to 2 decimal places.) Multiple Choice $29900 $16,860 $30,000 $26,400 2