Max wants to find our the exercise habits of local children. He plans to survey every third child he sees coming out of sporting goods store. Is this sample biased or unbiased?

Its biased because Max wants to find out the exercise habits of LOCAL children, but he is specifically going to an area where kids are mostly likely fit die to the fact that they are exiting a sporting good store, so yeah, Biased. Hope it helps.

The answer is 26 to 1