Anabolic steroid abuse has been increasing despite increased press reports of adverse medical and psychiatric consequences. In a recent study, medical researchers studied the potential for addiction to testosterone in hamsters (Neuroscience [2004]: 971€“981). Hamsters were allowed to self-administer testosterone over a period of days, resulting in the death of some of the animals. The data below show the proportion of hamsters surviving versus the peak self-administration of testosterone (mg). Fit a logistic regression equation and use the equation to predict the probability of survival for a hamster with a peak intake of 40mg.

n( ) -4589-0.0659x ; Survval Peak Intake Proportion P (micrograms) 10 30 50 70 90 0.980 49.0000 0.900 0.880 7.3333 0.500 0.170 3.8918 2.1972 1.9924 0.0000 -1.5856 9.0000 1.0000 0.2048