#21- Advertisement for a lactase supplement: Lactase, an

[ChicaRosa]

Why is C incorrect while B is correct?

I thought C would weaken it because if the body produces lactose as the body increases in age wouldn't that weaken the argument's conclusion for people to take lactose supplements?

Thank you!

[David Boyle]

Why is C incorrect while B is correct?

I thought C would weaken it because if the body produces lactose as the body increases in age wouldn't that weaken the argument's conclusion for people to take lactose supplements?

Thank you!

Hello ChicaRosa,

Answer C might weaken a little bit, although you could say that young people still may need to take lactase supplements. Also, we don't know how much more lactase the body produces with age; maybe it's only a tiny bit more and doesn't make much of a difference. So B is still the best answer, noting that most people probably don't drink a whole liter of milk at every meal.

Hope this helps,
David

[Esquire123]

Could we also say C is incorrect because the conclusion is specific to the "the number of subjects adversely affected" from the study mentioned and the study mentioned didn't specify the age groups of its subjects?

[Jeff Wren]

Hi Esquire,

That is correct. We don't have much information about the experiment, but if (and that's admittedly a big "if") the experiment had been properly conducted, then the people selected for the study would have been a representative sample of the population (based on age, sex, race, health, other factors, etc.).

Just to pick a number, let's imagine that 1/4 of the subjects suffered from lactose intolerance after drinking the milk in the experiment, and most of those people were younger or middle aged, while the elderly people in the experiment usually didn't have lactose intolerance (for the reasons given in Answer C).

Since the argument is "extrapolating from the number of subjects adversely affected" to claim that at least 50 million people in North America would benefit from these supplements, this 50 million could be a reasonable estimate based on the size of the overall population. For example, if 50 million people represented 1/4 of the total population, that would be a reasonable estimate based on the data from the experiment, and the fact that older people may not suffer lactose intolerance as much is completely consistent with this estimate.