Answer: Parents and children ( till the age of 5) of Norway
Explanation:
- The population in a survey is the group of people sharing common features or characteristics as per the researcher point of view.
Here, A large study of over 2000 parents and children in Norway found that toddlers who regularly slept less than 10 hours per night or woke frequently (three or more times) at night tended to experience more emotional and behavioral problems when they reached age five.
Since the study involved a large random sample of mothers and children and was conducted over several years.
So, the population of interest in this survey is "Parents and children ( till the age of 5) of Norway".