A marketing research firm wishes to determine if the residents of Caldwell, Idaho, would be interested in a new downtown restaurant. The firm selects a simple random sample of 120 phone numbers from the Caldwell phone book and calls each household. Only 62 of those called are willing to participate in the survey, and 56 participants would support a new downtown restaurant.
(a) The population of interest is
A. all households in the Caldwell phone book.
B. the 62 households that participated in the study.
C. the 120 phone numbers chosen.
D. all residents of Caldwell.
E. None of the above.
(b) The sample in this survey is
A. the 120 phone numbers chosen.
B. all residents of Caldwell.
C. all households in the Caldwell phone book.
D. the 62 households that participated in the study.
E. None of the above.
(c) The chance that all 120 phone numbers chosen are located in one particular neighborhood in Caldwell is
A. 120 divided by the size of the population of Caldwell.
B. exactly 0. Simple random sampling will spread out the locations of the phone numbers selected.
C. reasonably large due to the ''cluster'' effect.
D. the same as for any other set of 120 phone numbers.
E. None of the above.
I put a) D b) A c) D but I got one of them wrong, I don't know which one is wrong and what the answer is.
a) For the population, what about the residents who are not listed in the phone book?
(a) The correct answer is D. The population of interest is all residents of Caldwell, not just the households in the Caldwell phone book or the households that participated in the study. The marketing research firm wants to determine if the residents of Caldwell, Idaho, would be interested in a new downtown restaurant, so the population of interest is all residents of Caldwell.
(b) The correct answer is A. The sample in this survey is the 120 phone numbers chosen. The marketing research firm selected a simple random sample of 120 phone numbers from the Caldwell phone book, so the sample consists of these 120 phone numbers.
(c) The correct answer is B. The chance that all 120 phone numbers chosen are located in one particular neighborhood in Caldwell is exactly 0. Simple random sampling will spread out the locations of the phone numbers selected, so it is highly unlikely that all 120 phone numbers would be from the same neighborhood. Thus, the chance is 0.
The correct answers are:
(a) The population of interest is D. all residents of Caldwell.
This is because the marketing research firm wants to determine if the residents of Caldwell, Idaho would be interested in a new downtown restaurant. Therefore, the population of interest includes all the residents of Caldwell.
(b) The sample in this survey is D. the 62 households that participated in the study.
The sample in this survey refers to the 62 households that participated in the study. These households were randomly selected from the population of interest, which is all the residents of Caldwell.
(c) The chance that all 120 phone numbers chosen are located in one particular neighborhood in Caldwell is B. exactly 0. Simple random sampling will spread out the locations of the phone numbers selected.
The chance that all 120 phone numbers chosen are located in one particular neighborhood in Caldwell is exactly 0. Simple random sampling is designed to spread out the selection of phone numbers across the entire population, ensuring representation from different neighborhoods.