Question

7. (15 pts.) Plant Lead Uptake. Anaerobically digested sewage sludge and commercial fertilizer were applied to garden plots (10 ft. x 10 ft.) on which were grown turnips or Swiss chard. Each treatment was done in triplicate. After harvesting, the turnip roots or Swiss chard leaves were washed, dried, and analyzed for total lead. A) Determine the main and interaction effects of the sludge and fertilizer on lead uptake by the Swiss Chard Leaf plant. B) Calculate 95% confidence intervals for these effects. C) Identify which are significant.

7. (15 pts.) Plant Lead Uptake. Anaerobically digested sewage sludge and commercial fertilizer were applied to garden plots (10 ft. x 10 ft.) on which were grown turnips or Swiss chard. Each treatment was done in triplicate. After harvesting, the turnip roots or Swiss chard leaves were washed, dried, and analyzed for total lead. A) Determine the main and interaction effects of the sludge and fertilizer on lead uptake by the Swiss Chard Leaf plant. B) Calculate 95% confidence intervals for these effects. C) Identify which are significant. Table 5. Swiss Exp. Sludge Fertilizer Turnip Root Chard Leaf 0.46, 0.57, 0.43 2.5, 2.7, 3.0 0.56, 0.53, 0.66 2.0, 1.9, 1.4 0.29, 0.39, 0.30 3.1, 2.5, 2.2 0.31, 0.32, 0.40 2.5, 1.6, 1.8 1 none 2 110 gal/plot none 3 none 4 none 2.87 lb/plot 110 gal/plot 2.87 b/plot Source: Auclair, M. S. (1976). M. S. Thesis, Civil Engr. Dept., Tufts Univ.

Answer 1

A) the main and interaction effect of sludge and fertilizer on swiss Chard leaf are

effect Value

Sludge -0.8

Fertilizer 0.03

Sludge*Fertilizer 0.16

C)

From P-value in below table only effect due to Sludge is significant.

Term	Effect	T	P-value
Sludge	-0.8	-3.58	0.007
Fertilizer	0.0333	0.15	0.885
Sludge*Fertilizer	0.1667	0.75	0.477