The data shows the cash flow from three factories which are all owned by the same firm. The value of factory A, B and C is 10, 20 and 5, respectively. What is the average cash flow of the firm? What is the standard deviation of the cash flow of the firm?

A	B	C
5.81	22.94	6.91
20.24	20.24	3.39
19.05	17.57	2.98
21.97	26.56	4.59
14.16	12.03	1.90
10.80	14.29	2.01
0.33	24.58	8.88
3.84	22.44	6.54
29.34	18.17	0.92
12.56	28.88	7.38
-11.75	14.48	6.27
-4.67	9.38	4.11
6.81	16.41	3.83
-1.95	21.23	8.14
11.45	18.34	4.49
16.45	29.82	7.64
-0.33	15.93	5.78
9.08	19.96	5.15
24.30	23.85	3.70
15.48	25.23	5.68
7.52	25.70	7.09
26.90	21.86	3.24
15.12	23.38	5.33
-5.30	13.03	5.36
5.61	21.64	6.11
12.20	20.45	4.87
9.54	19.17	4.76
3.61	15.55	4.27
2.32	19.04	5.94
18.01	17.25	2.71