Assignment 4


Question 1.

The dataset discoveries found in the R base package lists the numbers of "great" inventions and scientific discoveries in each year from 1860 to 1959 (use "help(discoveries)" to get more information about the data set). Has the discovery rate remained constant over time?

Question 2.

The data was collected in a salmonella reverse mutagenicity assay. The predictor is the dose level of quinoline and the response is the numbers of revertant colonies of TA98 Salmonella observed on each of three replicate plates. Show that a Poisson GLM is inadequate and that some overdispersion must be allowed for. Do not forget to check out other reasons for a high deviance.

Question 3.

The data was collected from subjects in Denmark. Build a Poisson model to describe how marital status (i.e., single, married, or divorced) changes with age, taking care to give an understandable interpretation of the important parameter estimates. Under your model, predict the probability that a Dane, aged 55, is divorced.