I'm happy to help!
Here is the general process you should use for EXPLAIN DISCREPANCY problems:
1. Evaluate the
given circumstance / phenomenon.
2. Think about what you
would have expected / what the normal outcome would likely have been (this is usually unstated).
3. Think about why that's at odds with the actual
surprising outcome in this case.
4. Try to think of what information might be
missing (not always easy to anticipate; sometimes you won't know until you get to the answers).
5. Select an answer that
keeps both the given circumstance and the surprising outcome true.
Common wrong answer types:
- explain the given, but don't connect it to the surprising outcome
- support the
expected outcome rather than the surprising one
- equally justify the expected and the surprise (the "no-impact" scenario)
Here's your problem, edited - it seems to have contained a few typos:
The number of applications for teaching positions in Newtown's public schools was 5.7 percent lower in 1993 than in 1985 and 5.9 percent lower in 1994 than in 1985. Despite a steadily growing student population and an increasing number of teacher resignations, however, Newtown dose not face a teacher shortage in the late 1990's.
Which of the following, if true, would contribute most to an explanation of the apparent discrepancy above?
A. Many of Newtown's public school students do not graduate from high school.
B. New housing developments planned for Newtown are slated for occupancy in 1997 and are expected to increase the number of elementary school students in Newtown's public schools by 12 percent.
C. The Newtown school board does not contemplate increasing the ratio of students to teachers in the 1990's.
D. Teachers' colleges in and near Newtown produced fewer graduates in 1994 than in 1993.
E. In 1993 Newtown's public schools received 40 percent more applications for teaching positions than there were positions available.
Here's how we should break down this problem:
Given: 1. The number of applications for teaching positions in Newtown's public schools was 5.7 percent lower in 1993 than in 1985 and 5.9 percent lower in 1994 than in 1985. 2. There's a steadily growing student population and an increasing number of teacher resignations.
Expected outcome: you're think there would be a shrinking student-to-teacher ratio
Surprising outcome: Newtown does NOT face a teacher shortage in the late 1990's.
We need to keep true the lower # of applications, increasing # of teacher resignations, etc, while also keeping true that there is no teacher shortage.
Relevant information that we're missing:
- how does # of applications relate to # of teacher hires in the 80s v 90s? Were we hiring everyone who applied? Imagine that you only hired 1 teacher per year - it wouldn't matter how many applicants you had; if you had at least 1 qualified applicant, you'd never have a shortage.
- we're given info about resignations, but what about differences in firings, transfers, promotions - other things relevant to whether teachers stayed in their jobs or not?
- "shortage" is a vague term - have we redefined our teacher needs? Putting more students in each classroom, or hiring fewer specialty teachers? It's not clear how # of students relates to # of teachers needed.
Let's look at the answer choices:
(A) Many of Newtown's public school students do not graduate from high school.
- does this mean in the 80s or 90s? Without knowing that, we don't know if this explains a change.
- whether students graduate is not directly connected to how many teachers are needed.
(B) New housing developments planned for Newtown are slated for occupancy in 1997 and are expected to increase the number of elementary school students in Newtown's public schools by 12 percent.
- this provides more context for the GIVEN info that student population is increasing. That doesn't help to resolve the issue of teacher shortages.
(C) The Newtown school board does not contemplate increasing the ratio of students to teachers in the 1990's.
- this supports the EXPECTED outcome - if the ratio isn't going to change, we would have even more reason to expect that fewer applications + more students = teacher shortage.
(D) Teachers' colleges in and near Newtown produced fewer graduates in 1994 than in 1993.
- again, this helps to explain a GIVEN (perhaps this is why there are fewer applicants), but it doesn't explain why we don't have a shortage.
(E) In 1993 Newtown's public schools received 40 percent more applications for teaching positions than there were positions available.
-A shortage would result from having fewer (qualified) applicants than there were teaching positions available. If in 1993 they had more applicants than positions to fill, then it wouldn't matter if this was more or fewer applications than in the 80s - we can still fill all of the available positions, so there is no shortage (since the argument doesn't address quality of applicants, etc, we can ignore that). This doesn't undermine any of the given information, and it supports the surprising outcome of no shortage.
The answer is
E. Hope this helps!
