A manufacturer of cat food was planning to survey households in the US to determine purchasing habits of cat owners. Among the questions to be included are those that relate to

1. Where cat fat is primarily purchased.
2. Whether dry or moist cat food is purchased.
3. The number of cats living in the household.
4. Whether the cat is pedigreed.

a. Describe the population.

b. For each of the four items listed, indicate whether the variable is categorical or numerical.