A researcher is trying to determine the doubling time for a population of the bacterium Giardia lamblia. He starts a culture in a nutrient solution and estimates the bacteria count every four hours. His data are shown in the table.

(a) Make a scatter plot of the data.

(b) Use a graphing calculator to find an exponential curve f (t) = a · b^t that models the bacteria population t hours later.  

(c) Graph the model from part (b) together with the scatter plot in part (a). Use the TRACE feature to determine how long it takes for the bacteria count to double.   

Transcribed Image Text:

Time (hours) | 16 4 | 20 24 12 Bacteria count (CFU/mL) 37 63 105 | 130 | 173 47 78 4- G. lamblia