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The table below shows the probability distribution of past records of the number of breaks of a heavy-duty document scanning machine in a week. It is estimated that each breakdown costs the company $2,874 in lost business. Find the standard deviation of the weekly cost from breakdowns of this machine. No. of breaks (X) 0 1 2 3 A P(X) 0.11 0.2 0.16 0.45 0.08