(a) a city manager wants to poll residents ab...

(a) a city manager wants to poll residents about a park renovation. which of the following best describes a stratified sample of residents? the first 64 residents who walk into city hall one day are easily accessible. so, the city manager selects these residents. the city manager takes a list of the residents and selects every 4th resident until 64 residents are selected. the city manager forms 4 groups of residents based on the residents incomes. then, she selects 16 residents at random from each group. (b) a host on a cruise ship wants to collect data on the time passengers spend at various activities on board. which of the following best describes a convenience sample of passengers? the host forms groups of 8 passengers based on the passengers ages. then, he randomly chooses 7 groups and selects all of the passengers in these groups. the host selects the first 56 passengers who board because these passengers are easily accessible. the host assigns each passenger a different number. using a random number table, he draws 56 of those numbers at random. then, he selects the passengers assigned to the drawn numbers. every set of 56 passengers is equally likely to be drawn using the random number table.

Answer

# Brief Explanations: (a) In a stratified sample, the population is divided into subgroups (strata) based on a relevant characteristic (here income), and then samples are taken from each subgroup. The first option is a convenience sample as it just selects easily - accessible residents, and the second is a systematic sample. The third option divides residents into income - based groups and samples from each, which is stratified sampling. (b) A convenience sample is one that is selected based on ease of access. The first option is a form of cluster sampling, the second option selects the first 56 passengers who board which is easy to access (convenience sample), and the third is a simple random sample. # Answer: (a) The city manager forms 4 groups of residents based on the residents’ incomes. Then, she selects 16 residents at random from each group. (b) The host selects the first 56 passengers who board because these passengers are easily accessible.