IQ test score is assumed normally distributed with known standard deviation of 10 units. The sample mean score from 75 people was 105.2 units. 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, 347 is entered as 347.0, 3.52 is entered as 3.5, 0.2750 is entered as 0.3, -0.564 is entered as -0.6