S= (12-14)+(14-14)+(9-14)+(21-14)2 (2)+(0)+(-5)+(7) 14+0+25+49 = 19.5 What is the first error he made in computing the standard deviation? Yuri failed to find the difference between each data point and the mean. Yuri divided by n instead of n-1. Yuri did not subtract 9 - 14 correctly. Yuri failed to square -2 correctly.