11: And the answer is…

Pretty clever so far… but the whole reason we got this data in the first place was to figure out how fast the bacteria can double, and so far we still haven’t managed to do that.

If we look at the actual data again, we can see that we weren’t lucky enough to see the actual number doubling, so that won’t help.

We can determine doubling time roughly by reading it off a graph. To do this, pick a starting population (on the y axis) which falls within the exponential growth window. Find the doubled population and check that it also falls within the exponential growth window. Find the amount of time elapsed (on the x axis) between the two population readings. This is the approximate doubling time. (Note: its a little hard to find the doubled population because this is a log-transformed graph. The applet will help you with this.)

Look at the graph again and follow the directions to find the actual doubling time.

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Hooray! Now we know! The doubling time was about 27 minutes.