The maximum distance (ft.) 9 drivers could read a road sign was recorded. It is reasonable to assumed these distances are normally distributed. The distances were: 440, 490, 600, 280, 540, 600, 240, 440, 360. Find a 90% confidence interval for the population mean. What is the UPPER BOUND? ______________________________ Note: Enter XXX.X AT LEAST ONE DIGIT BEFORE THE DECIMAL, ONE AFTER and round up. Thus, 134.78 is entered as 134.8, 35.292 is entered as 35.3, .2750 is entered as 0.3, -.5647 is entered as -0.6