he average age of chief executive officers (CEO’s) in a large sample of companies is 57. The average age of CEO’s in those same companies 20 years ago was approximately eight years younger. On the basis of those data, it can be concluded that CEO’s in general tend to be older now.
Which of the following casts the most doubt on the conclusion drawn above?
Good question and this sort of reasoning is used in real life also.
Conclusion : CEOs are older now in general .
Arrived at this conclusion : By comparing ages of a specific group.
Assumption : This particular group is representative of the overall industry 20 years ago and even now.
Break this and you have your weaken answer. Say the sample excludes all the companies whose ceo is in his 20s. Then it is invalidated as it is not accurate representation of entire industry.
(A) The dates when the CEO’s assumed their current positions have not been specified. --->
I am not interested in writing history of a company . My conclusion is about ceos are older (B) No information is given concerning the average number of years that CEO’s remain in office. --->
It is not talking about sample and ceos remain in office so what do get about if they are getting older or younger. Nothing (C) The information is based only on companies that have been operating for at least 20 years. --> Breaks the sample. Think of it this way, in the last 20 years, if so many companies with young ceos have started operations then the sample is not taking these new changes but sticking to its old companies that were there 20 years back. So average age of ceo at present is lesser. Thus, this is right answer.(D) Only approximate information is given concerning the average age of the CEO’s 20 years ago. --> ofs
(E) Information concerning the exact number of companies in the sample has not been given. --> ofs