11.Taken together, some 2,000 stocks recommended on a popular television show over the course of the past 12 years by the show's guests, most of whom are successful consultants for multibillion-dollar stock portfolios, performed less uccessfully than the market as a whole for this 12-year period. So clearly, no one should ever follow any recommendation by these so-called experts.

E. The stock portfolios for which the guests were consultants performed better for the past 12-year period than the market as a whole.

The argument clearly states the following:
- taken together, the 2000 stocks recommended performed badly
- no one should follow these experts' advice

E is a weakening statement because it does not refer to the 2000 stocks recommended throughout the life of the show, but to the portfolios that the successful consultants recommended on their own. The other recommendations might have been pretty disastrous (hence the poorer performance of the 2000 combined stock) or the portfolio obtained by putting the 2000 stock together was not carefully selected (just made up of piling all the recommendations together). These two elements explain why the 2000 stocks did not perform well, but advice from consultants taken independently is still a good idea.

Thanks DANAJ
if i have understood your explanation correctly then.rephrasing the whole thing to my level , it goes something like this

the conclusion is that no one should ever follow any recommendation by these so-called experts because the some 2,000 stocks recommended by these experts have performed poorly in past 12 years , so there advce is not worthy enough.
E weakens this logic by stating that however their advice to multibillion-dollar stock portfolios has been successful .Thus proving the logic wrong and hence weakening the argument

Yes, the basic idea is that when you put all the recommendations ever made together, it might not be a good thing. However, if you take them separately, then they are pretty good.

thephoenix wrote:Thanks DANAJ
if i have understood your explanation correctly then.rephrasing the whole thing to my level , it goes something like this

the conclusion is that no one should ever follow any recommendation by these so-called experts because the some 2,000 stocks recommended by these experts have performed poorly in past 12 years , so there advce is not worthy enough.
E weakens this logic by stating that however their advice to multibillion-dollar stock portfolios has been successful .Thus proving the logic wrong and hence weakening the argument

@thephoenix

U took it wrongly.
No where it is said the multibillion -dollar stock portfolios performed better than the market as a whole.

Argument is concerned about return on recommended stocks vs return from market as a whole.

Conclusion is no one should follow any recommendation by these experts. And E weekens it by saying portfolios for which the guests were consultants gave better return than market as a whole. It means people should follow recommendations from consultants(who r a part of guests) and not from all guests.