Final answer:
In the working set model with τ = 3, the reference string of a process is given. It represents the sequence of memory locations that the process accesses. The reference string helps determine the working set of a process.
Step-by-step explanation:
In the working set model with τ = 3, the reference string of a process is given. The reference string represents the sequence of memory locations that the process accesses during its execution. It helps in determining the working set of a process, which is the set of all pages that a process references within a particular time window.