Calculating the standard deviation for TVs at ABC Electronics The planner at ABC Electronics is trying to optimize stocking and ordering for a popular 50- inch plas TV it stocks. The first step is to look at the pattern of demand to calculate the rate of sales. After looking back over the past 10 weeks of sales, the planner has determined the actual sales on the TV and has placed the values in the table below. The average of number of TVs sold during that period was 125. Week Sales Forecast Actual Sales Absolute Deviation Deviation^2 1 25 84 2 125 78 3 125 155 4 125 155 5 125 170 6 125 72 7 125 75 8 125 172 9 125 67 10 125 166