Final answer:
The feedback Chad receives from his ironman training group is an example of informational social influence.
Step-by-step explanation:
The feedback Chad receives from his ironman training group is an example of informational social influence.
Informational social influence refers to the influence that others have on our beliefs, attitudes, and behaviors when we are uncertain about a particular situation.
In this case, Chad is uncertain about which sunscreen to purchase, so he seeks the opinions of his training group to guide his decision-making process.