Answer:
a. The correlation between drinking coffee and longevity among older people
b. The population is the entire population of older people
The sample is the over 400,000 older people from eight states
c. It is an observational study
Step-by-step explanation:
a. A statistical question is a question that results in different answers from different respondents. Here the statistical question the researchers are trying to answer is if there is a correlation between drinking coffee and longevity among older people
b. The population is the entire population of older people and the sample is the over 400,000 older people from eight states
c. An observational study is one in which the researchers sought or collect data based on what is obtainable and make conclusions based on the sought or obtained data. An experiment is one in which the effects of inputs from the researchers on a group is recorded
From the description of the question, therefore, the study is observational.