Answer:
a) a cohort.
Explanation:
Cohort is a term which is used in marketing, statistics and demography. It describes a group of people who share a defining characteristic - a group of people who share a common event. This type of data is more accurate than period data, also used by the demographers.
On the other side, cohort data has some disadvantages. It can take a long amount of time to collect all the necessary data for a study. Also it can be really costly, and a lot of money is necessary to conduct a successful research. Two important cohort study types are prospective and retrospective cohort study.
Demography is defined as the statistical study of the populace, education, and other criteria. A cohort in marketing and demography is the sharing of similar traits in a group of subjects.
The correct statement for the given blank is:
To a demographer, a group of people that begin something at the same time is known as a cohort.
The cohort is used in statistics and demography to define the group of people sharing defining and common traits. The group or populace shares a common event.
The data based on the cohort is more precise than the period data.
Some of the disadvantages of the cohort are it is time taking, can be expensive, and requires lots of resources.
Therefore, the correct term is the cohort.
To know more about the cohort, refer to the following link:
https://brainly.com/question/7580591
