NCAA: Since implementing a 64-game format in 1985

[payal919]

IR: Graphs Question Bank

Since implementing a 64-game format in 1985, the NCAA men’s basketball tournament has "seeded," or given initial quality rankings to, 16 teams in each of 4 divisions. In the first round in each division, the lowest seed (#16) plays the highest seed (#1); #15 plays #2; and so forth. The graph displays the win percentage of the lower (worse) seed in the first round across all divisions. The first column in each pair (white) shows the win percentage during the period 1985-2005, inclusive (out of 84 games); the second column (shaded blue) shows the win percentage during the period 1985-2011, inclusive (out of 108 games). Since 1985, the #16 seed in any division has never beaten the #1 seed in the first round.

Question # 1:
During the period between 2006 and 2011, inclusive, the #11 seed won approximately____of its first-round games against the #6 seed.

Choices:
31%
36%
41%
46%
51%

OA: 46%.


Graph Statistics for # 11:
1985-2005: roughly 30%
1985-2011: roughly 33%

My thought process:
1985-2005: 84 games were played, so 30% of 84= 25.2
1985-2011: 108 games were played, so 33% of 108 = 35.64

The period between 2006 to 2011: 35.64-25.2 = 10.44
Games played during this period: 108-84 = 24

#11 won: 10.44/24 =43.5%

However, the correct answer is 46% because the games played were rounded to 25 and 36 which resulted in 11/24 = 46%

Please assist me in figuring out why the rounding was necessary here and why I was unable to get an answer close to 46% using the exact figures? Should i always use the rounding rule if the question says approximate?
My answer was in the middle of two choices 41% and 46%. What should I do if I don't round? how to know which answer to pick if I forget to round?

[RonPurewal]

Please assist me in figuring out why the rounding was necessary here and why I was unable to get an answer close to 46% using the exact figures?

You're not thinking about what the numbers mean.

We're talking about the number of basketball games won by certain teams. (Is it possible for a team to win 35.64 games?)

If common sense dictates that some quantity has to be a whole number, then it has to be a whole number.

What should I do if I don't round?

In this context, if you don't round, the result is nonsense. You can't win a fractional number of games.