Answer:
The answer is stratified sampling.
Explanation:
Miranda divides up her day into three parts: morning, afternoon, and evening.
She then measures her heart rate at 2 randomly selected times during each part of the day.
This sampling method is Stratified sampling.
This is because Miranda created separate groups and took samples from each group.
Stratified sampling is defined as dividing the population into separate groups or strata and then drawing a sample from each group.