MA207-B Spring 2008 Regression Project

MA207-B Spring 2008 Regression Modelling Project - Problem 7

The zebra mussel, Dreissena polymorpha, is native to southeast Russia but was imported by ship traffic to the Great Lakes. They continue to appear in freshwater lakes and rivers, possibly spread by recreational boats.

The Michigan Department of Natural Resources has been monitoring the zebra mussel population at a lake in the southwest portion of the state since they were first discovered there in 1995.

Each year, samples are taken to measure the average population density, in mussels per square meter.

Use the data in your comma delimited file to construct a regression model for the population density as a function of time.

You should answer the questions on the assignment page that apply to all problems.

For this specific problem, answer the following questions:

Did you use a log transform in this model? If so, explain why you chose to use a transform.
Explain how you used the regression model to estimate the annual percentage growth.
How would you interpret the intercept of the regression line in this problem?
Were there any outliers or questionable data points? If so, how did you handle them?
What population density would you project for 2012?

Hint: This problem is easier if you renumber the years beginning at zero. This makes the intercept easier to interpret. The slope of the regression line will be the same as if you had not renumbered.