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 $2,850 in lost business. Find the standard deviation of the weekly cost from the breakdowns of this machine.

No. of breaks (X)	0	1	2	3	4
P(X)	0.14	0.34	0.2	0.15	0.17