Find Ex by adding all of the values of the observations together. Then use that number to calculate the sample mean. Recall that n = 9. (Round your answer to four decimal places.) X = Ex n (No Response) 11,437 = 9 (No Response) 1,270.7778 Step 3 Recall that the formula for the sample standard deviation. S = Ex- (EX) n n-1 Recall that Ex = 11,437 and n = 9. Find Ex by squaring each observation and then by adding the results together. Then use the sum of the squared observations to calculate the sample standard deviation. (Round your answer to four decimal places.) x (Ex) n n-1 11,4372 9 9-1