For the purposes of this question a household corresponds to

For the purposes of this question a household corresponds to a single residential address, while household size is the number of individuals living at that address. Say you conduct a simple random sample of individuals living in Vancouver. Those sampled are asked to report their household sizes. The sample average of household size will be:

A. systematically biased upwards as an estimator of the average size of Vancouver households.
B. systematically biased downwards as an estimator of the average size of Vancouver households.
C. sensible as an estimator of the average size of Vancouver households.

Solution

Note that the mean of a sampling distribution is the population mean, and the sample mean is an unbiased estimator of the population mean. Thus,

C. sensible as an estimator of the average size of Vancouver households (answer)