According to a Gallup poll, about 90% of all American adults owned a cell phone at the time of the poll.

The results are based on telephone interviews with a randomly selected national sample of 998 adults, 18 years and older.

What was the population of interest in this Gallup Poll?

The population of interest are all the American adults, 18 years and older.

Explanation:

This is a common statistic method.

If you want to estimate something about a big population, you select a random sample of the population, and estimate for the entire population.

For example, if you want to estimate the proportion of residents of Buffalo, New York, that are Buffalo Bills fans, you are going to ask, for example, 1000 Buffalo residents. Your population of interest are all the residents of Buffalo, New York.

According to a Gallup poll, about 90% of all American adults owned a cell phone at the time of the poll. The results are based on telephone interviews with a randomly selected national sample of 998 adults, 18 years and older.

What was the population of interest in this Gallup Poll?

The sample was of 998 American adults, 18 years and older.

So the population of interest are all the American adults, 18 years and older.