Sample	Gravimetric	Spectrophotometric
1	54.7	55
2	58.5	55.7
3	66.8	62.9
4	46.1	45.5
5	52.3	51.1
6	74.3	75.4
7	92.5	89.6
8	40.2	38.4
9	87.3	86.8
10	74.8	72.5
11	63.2	62.3
12	68.5	66