Test: Mean: SD. Hemoglobin # X Difference from X Squared 11.8 Difference from X Range +/- 1SD Range +/- 2SD Range +/- 3SD 2 1 1 . 8 3 11 .8 4 11.8 Procedure for calculating mean and 5 11. 9 standard deviation: 6 11- 9 1. Record control data into the first column 2. Find the sum of column one by adding 7 1 1 .9 all values together 8 11 .9 3. Calculate the average, x 4. Calculate and record in column two 9 12.0 individual differences from the average 10 12.0 5. Square each individual difference in column two, and record in column three 11 12.0 6. All column three to get the total 7. Calculate the Standard Deviation using 12 12.0 the equation below 13 12. 1 X = each individual measurement 14 12.2 N = total number of measurements 15 12. 1 X = mean 16 12. J Mean = Sum of X 17 12.2 N 18 12.2 Standard Deviation = 19 12.2 Sum of Squared Difference from X 20 12.2 N-1 Sum