Table 1.

LC50 of ZnONPs on O. niloticus.

Fish Groups	Fish No.	Concentration of ZnONPs. µg/l	No. of dead fish after 96 h	a	b	a X b	Σ (a × b)
1	10	Zero	Zero	Zero	Zero	Zero
2	10	1	1	1	0.5	0.5
3	10	2	2	1	1.5	1.5
4	10	3	3	1	2	2.5
5	10	4	5	1	4	4
6	10	5	6	1	5.5	5.5
7	10	6	8	1	7	7
8	10	7	9	1	8.5	8.5
9	10	8	10	1	9.5	9.5
							39

a = Constant factor between two successive doses, b = The mean of dead fish in the groups.

n = Number of fish in each group Σ = The sum of (a × b).

96 LC₅₀ = highest dose - Σ (a × b)/n.

8–39/10 = 8–3.9 = 4.1 µg/l.