Test: Mean: SD: RBC # X Difference Squared from X Difference from X 3.98 Range +/- 1SD Range +/- 2SD Range +/- 3SD 2 3.98 3 3 . 9 9 4 4.00 5 4.00 Procedure for calculating mean and standard deviation: 6 4.01 1. Record control data into the first column 7 4.02 2. Find the sum of column one by adding all values together 8 4.02 3. Calculate the average, X 9 4.04 4. Calculate and record in column two individual differences from the average 10 4.04 5. Square each individual difference in 11 4.05 column two, and record in column three 6. All column three to get the total 12 4. 0 6 7. Calculate the Standard Deviation using the equation below 13 4. 06 14 4.07 X = each individual measurement N = total number of measurements 15 4. 08 X = mean 16 4.08 Mean = Sum of X 17 4.09 N 18 4. 10 Standard Deviation = 19 4. 17 20 4. 13 Sum of Squared Difference from X N-1 Sum