Response of Solenopsis invicta Workers to Polyoxyethylene Tridecyl Ether Surfactants in Relation to Hydrophilic-lipophilic Balance

Table 3: Result of regression analysis on mortality data in glass-vial bioassay.

Concentration	Variable	Parameter estimated (SE)	95% CL	t Value	P Value
0.018 μg/cm²	Intercenpt	163.37 (9.07)	145.17 - 181.57	18.01	< 0.001
	HLB number	-12.77 (0.85)	-14.48 - -11.05	-14.95	< 0.001
0.036 μg/cm²	Intercept	216.81 (11.77)	193.20 - 240.42	18.43	< 0.001
	HLB number	-15.82 (1.11)	-18.05 - -13.60	-14.29	< 0.001

r² was 0.80 and 0.81 for 0.018 μg/cm² and 0.036 μg/cm² respectively.