The 3 different ways to estimate the lc50 are exposure are concentration vs % mortality (linear graphically), log of exposure concentration vs % mortality on the probit scale (graphically) and an excel spreadsheet program that determines lc50 and confidence intervals.

1. you have used 3 different ways to estimate the lc50, how comparable are these estimates? is one better than the other? why?

Extensive and unusual cold snaps have occurred here recently. is this evidence that global warming is lessening or not occurring? no—although the long-term trend is for warming, short-term weather patterns can still be variable. no—melting of glaciers and ice caps is making the oceans cooler, which can cause cold snaps. yes-- if global warming really were occurring, cold snaps wouldn’t happen. yes—due to global warming, weather patterns should be become less—not more—variable.