In one study, the life spans of 129 robins were monitored over a 4-year period. The equation

can be used to calculate the number of years y required for x percent of the robin population to die. For example, to find the time when 40% of the robins had died, substitute x = 40 into the equation. The result is y ≈ 0.53, or about half a year. Find the percentage of the robins that had died after 2 years. 

Transcribed Image Text:

y 2 - log(100 0.42 x)