Identifying Flaws of Sampling - GMAT Verbal

The two pieces of evidence we are offered here do not allow us to make a strong enough conclusion to connect yachts to hot tubs. The first sentence tells us that an unspecified “many” of the yachts in Miami have a hot tub, but we do not know how many of these yachts are older models and how many are newer models. The second sentence tells us that sold were older models: that would imply that sold were newer models. Just because none of the older models that sold in the past fifteen years had built-in hot tubs does not necessarily mean people are avoiding buying older model yachts without hot tubs. There could be any number of explanations for this data. The only thing we can infer is that since only were older models, at least some newer models were sold.