Acoach wants to see how long the members of the water polo team can hold their breath. he times each member and finds that the average is 45 seconds. what type of study is this? experiment observational study randomized trial double-blind study

Observational study

Step-by-step explanation:

In an experiment, one group is given a treatment and one group is a control group.  There is only one group here; this is not an experiment.

A randomized trial involves some sort of random selection of participants; there is no randomization here, so this is not a randomized trial.

In a double-blind study, neither the participants nor the researcher are aware of the participants in the study; this is not a double-blind study.

The coach observes the amount of time the members of the team can hold their breath.  This is an observational study.

the answer is d

step-by-step explanation: