Paper 1, Section I, J

Statistical Modelling
Part II, 2018

The data frame Ambulance contains data on the number of ambulance requests from a Cambridgeshire hospital on different days. In addition to the number of ambulance requests on each day, the dataset records whether each day fell in the winter season, on a weekend, or on a bank holiday, as well as the pollution level on each day.

A health researcher fitted two models to the dataset above using RR. Consider the following code and its output.

 > head (Ambulance)  Winter Weekend Bank. holiday Pollution. level Ambulance.requests 1 Yes Yes No High 16\begin{aligned} & \text { > head (Ambulance) } \\ & \text { Winter Weekend Bank. holiday Pollution. level Ambulance.requests } \\ & 1 \text { Yes Yes No High } 16 \end{aligned}

3 No No No High 224 No  Yes  No  Medium 11\begin{aligned} & 3 \text { No No No High } 22 \\ & 4 \text { No } \quad \text { Yes } \quad \text { No } \quad \text { Medium } \quad 11 \end{aligned}

Define the two models fitted by this code and perform a hypothesis test with level 1%1 \% in which one of the models is the null hypothesis and the other is the alternative. State the theorem used in this hypothesis test. You may use the information generated by the following commands.