You plan to sample residents of registered nursing homes in your county. You obtain a list of all 97 nursing homes in the county, which you number from 01 to 97. Using random numbers, you choose five of the nursing homes. You obtain lists of residents from those five homes and interview all the residents in each home.
a. Are the nursing homes clusters or strata?
b. Explain why the sample chosen is not a simple random sample of the population of interest to you.