In a study of a marine tubeworm, scientists developed a model for the time T (measured in years) required for the tubeworm to reach a length of L meters. On the basis of their model, they estimate that 170 to 250 years are required for the organism to reach a length of 2 meters, making this tubeworm the longest-lived noncolonial marine invertebrate known. The model is:                  

  

      

  

Here b is a constant that requires estimation. What is the value of b if the lower estimate of 170 years to reach a length of 2 meters is correct? What is the value of b if the upper estimate of 250 years to reach a length of 2 meters is correct?    

 

T = 20el. 28 b