More practice. Given s = n-1 find s when 21 = 3, X2 = 7, 13 = 2, a = 4, n - 3. Remember order of operations! Simplify from the innermost grouping symbol, which is a sum. First, find (x x) = (x - 2)2 + (22 2)2 + (13 2)2 Write the sum on scratch paper, with the correct numerical values. Use order of operations to simplify. (21 - )2 + (22 - 2)2 1 23 1) Now that you have found the sum of the squared differences, divide by n-1. n-1 Finally, take the square root of this quotient. Round to one decimal place