Exponential and logarithmic regression

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Exponential and logarithmic regression

• Section 6.8

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expl

• Biology A colony of bacteria
• initially increases according
• to the law of uninhibited
• growth. A biologist collects
• the data to the right for this
• bacteria.
• a.) Draw scatter diagram.
• b.) Fit an exponential curve to data.
• c.) Express curve in form

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• d.) Graph the exponential function found in part
  b or c on the scatter diagram.
• e.) Using the equation from part b, predict the
  population at t 7 days.

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• For part c, we have the two equations
• and . We will try to combine them.
• Since the first tells us the initial amount is
  72.46, well use that for N0. Setting the
  expressions for N(t) equal, we get

Solve this for k.
So the equation is
Part e asks you to evaluate the function when t
7. Youll get 2413 bacteria.
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Worksheet

• Exponential regression on your calculator
  explains the idea behind regression and shows you
  how to calculate exponential and logarithmic
  regression curves using your TI82, 83, 85, or 86.
• 6.8 homework 1, 4, 7