Participants at a continuing legal education

[Guest]

Participants at a continuing legal education seminar were asked to evaluate the seminar schedule, location and topic selection to determine whether changes
would increase attendance at next year’s seminar. A majority of the evaluations recommended that the seminar schedule be changed so that the sessions
would be held from 8:00 a.m. to 4:00 p.m. instead of the current 9:00 a.m. to 5:00 p.m. schedule. Based upon the results of the evaluations, the sponsors of
the seminar decided to change to an earlier schedule for next year’s program.

Which of the following selections, if true, would most prove the sponsors right in their decision to change to an earlier schedule next year?

(A) Approximately 85% of the people who received evaluation forms completed their forms and handed them in.
(B) Other seminar sponsors have made changes in their programs based on comments they have received in evaluation forms.
(C) About the same percentage of people attending the seminar wanted the earlier schedule as those who returned their evaluation forms.
(D) An earlier seminar schedule would make commuting easier for the participants.
(E) A significantly larger percentage of people who preferred the earlier schedule returned their evaluation forms than people who preferred the 9:00 a.m. to 5:00 p.m. schedule.

OA is C. My answer is E, because it is clearly stated in the stimulus that a larger percentage of people who preferred the earlier schedule (8:00 am - 4:00 pm) returned their evaluation forms.

Please correct me if i'm wrong here.

[esledge]

Please cite the source (author) of this problem. We cannot reply until then. If no source is cited, we will have to delete the question just to be sure we are not violating someone else's copyright. Thanks!

[Guest]

source is NOVA GMAT book.

thanks.

[esledge]

OA is C. My answer is E, because it is clearly stated in the stimulus that a larger percentage of people who preferred the earlier schedule (8:00 am - 4:00 pm) returned their evaluation forms.

Please correct me if i'm wrong here.

Be careful, the argument actually said "A majority of the evaluations recommended that the seminar schedule be changed." (italics added by me) This means only that of those evaluations collected, a majority indicated a preference for the earlier time. It tells us nothing about how many evaluations were collected, or what percent of the seminar participants returned them. For example, there could have been 100 people at the seminar, but only 3 evaluations collected. If 2 of those 3 indicated a preference for the earlier time, this premise would be truthful though misleading.

That's why three of the choices, (A), (C), and (E), deal with the response rate. To best support the decision to move to an earlier schedule, we need a choice that proves that the surveys accurately reflect the wishes of all the seminar participants. To decide between the seemingly similar (A), (C), and (E), read critically and mathematically.

(A) Seems to strengthen, but probably not. If 85% of the people who received evaluation forms completed their forms and handed them in, then at least 85%/2 = 42.5% ("a majority of the evaluations") want the earlier time. Worst case, the other 15% don't want the schedule changed. That means it's possible that a majority actually prefers the later time. We also must wonder whether "people who received evaluation forms" is the same as "people who attended the seminar"--did everyone get the forms in the first place?

(B) Other seminar sponsors are irrelevant.

(C) Strengthens, as it equates "people attending the seminar" with "those who returned their evaluation forms." In other words, if a majority of the evals prefered the earlier time, then a majority of all the participants want the earlier time.

(D) Ease of commute is irrelevant.

(E) Weakens, as it indicates that fewer people prefer the earlier schedule than the surveys indicate. In other words, the people who prefer the earlier schedule are over-represented in the surveys.