The table gives information about teacher absenteeism in 21 school

Question

The table gives information about teacher absenteeism in 21 school systems worldwide for 2012-2013. For each school system, the table gives the country where it is located, the number of teachers it employed in 2012-2013, the average number of days those teachers were absent, and the percent of those teachers who were chronically absent (absent 18 or more days).

Scool system 
 Location(country) 
 Number of teachers 
 Average days absent 
 Percent chronically absent 
 
  1 
 A 
 5,636 
 10.19 
 11.12 
 
  2 
 B 
 2,382 
 13.87 
 36.82 
 
  3 
 C 
 1,778 
 11.77 
 14.12 
 
  4 
 C 
 2,896 
 15.6 
 33.81 
 
  5 
 C 
 2,151 
 14.82 
 32.03 
 
  6 
 A 
 9,395 
 11.93 
 15.22 
 
  7 
 A 
 8,266 
 9.68 
 13.65 
 
  8 
 D 
 6,642 
 13.91 
 27.12 
 
  9 
 E 
 974 
 9.56 
 12.22 
 
  10 
 F 
 21,867 
 9.2 
 10.61 
 
  11 
 B 
 59,750 
 8.8 
 7.43 
 
  12 
 B 
 10,108 
 12.52 
 12.44 
 
  13 
 G 
 9,114 
 8.8 
 8.98 
 
  14 
 G 
 1,608 
 11.56 
 17.29 
 
  15 
 F 
 2,035 
 12.05 
 19.46 
 
  16 
 A 
 5,977 
 13.37 
 21.69 
 
  17 
 F 
 4,991 
 11.78 
 18.01 
 
  18 
 F 
 3,286 
 9.87 
 12.63 
 
  19 
 F 
 1,290 
 11 
 15.04 
 
  20 
 E 
 1,710 
 9.77 
 10.94 
 
  21 
 D 
 11,362 
 8.63 
 6.07

For each of the following statements, select  Yes  if, based on the information provided, it can be inferred that the statement is true. Otherwise, select  No .

KarishmaB · Accepted Answer

For the 21 school systems in the table, the number of chronically absent teachers in the school systems in Country D is greater than the number of chronically absent teachers in the school systems in Country G.

Sorting school systems by location, we find 2 in D and 2 in G.

The number of chronically absent teachers in the school systems in Country D = 27% of 6.6k + 6% of 11k
The number of chronically absent teachers in the school systems in Country G = 17% of 1.6k + 9% of 9k

27% of 6.6k is much much greater than 17% of 1.6k while 6% of 11k will be slightly less than 9% of 9k.
So number of chronically absent teachers in the school systems in Country D will be more.

ANSWER: YES

For the 21 school systems in the table, there is a positive correlation between the number of teachers and the average number of days the teachers were absent.

Positive correlation means if one variable increases, the other increases too. Negative correlation means if one variable increases, the other decreases. 
Sort by 'number of teachers'.
As the  'number of teachers'  increases, the  'average number of days the teachers were absent ' sometimes increases sometimes decreases. There is no set pattern. Hence the two variables are not positively correlated. There seems to be no correlation between them.

ANSWER: NO

The school system in the table with the median number of teachers is in the same country as the school system in the table with the median percent of chronically absent teachers.

Sort by ' number of teachers' and look at the 11th row.  ​​​​​​​(median will be the 11th value)
Median number of teachers are in country F (4991).

Sort by  'percent of chronically absent teachers' and look at the 11th row.  (median will be the 11th value)
Median percent of chronically absent teachers is in country C (14.12%)

They are not in the same country.

ANSWER: NO

SomeOneUnique · Answer

kop18  
 sayan640

Q2.   is about positive correlation. 
 To get these questions correct, we need to figure out the direction of one column when sorted based on another column. 
 To establish a positive correlation, we should expect to see an increase as we move forward along both columns.

For a better understanding: 
 If we imagine a graph of positive correlation it should be an approximate upward-moving diagonal from the origin to the opposite upper right corner of the graph. (Given data plot is not required to be precisely a straight diagonal but should be in the direction of the expected diagonal or somewhere near the expected diagonal.)

With the given values of 'Number of teachers' and 'Average days absent'  we are NOT getting an expected upward-moving diagonal  on the graph. 
 I am attaching a rough graph to visualize the plot of given data points.

Because  we are NOT getting an expected upward-moving diagonal  no positive correlation exists between the 2 mentioned columns.

Bunuel · Answer

https://gmatclub.com/forum/download/file.php?id=86222 • For the 21 school systems in the table, the number of chronically absent teachers in the school systems in Country D is greater than the number of chronically absent teachers in the school systems in Country G. Sort the table by Location so D rows and G rows are grouped. For each D row, multiply teachers by percent chronically absent, then add: System 8: 6,60 * 27% ≈ 1,800 System 21: 11,000 * 6% ≈ 660 Total for D ≈ 2,460 Do the same for G: System 13: 9,000 * 9% ≈ 810 System 14: 1,600 * 17% ≈ 270 Total for G ≈ 1,080 Compare 2,460 to 1,080. D is greater. Answer: Yes. • For the 21 school systems in the table, there is a positive correlation between the number of teachers and the average number of days the teachers were absent. A positive correlation means that as the number of teachers rises, the average number of days absent should generally rise too. To check this, sort the table by Number of teachers in ascending order. You now have 21 rows, giving 20 changes as you move from one row to the next. For each move, compare the Average days absent value. You’ll see that in half the moves, the value goes up, and in about half it goes down. So, there’s no consistent upward trend. Therefore, there is no positive correlation between the number of teachers and the average number of days absent. Answer: No. • The school system in the table with the median number of teachers is in the same country as the school system in the table with the median percent of chronically absent teachers. There are 21 rows, so the median is the 11th after sorting. Sort by Number of teachers ascending and read the 11th row. 11th is 4,991 teachers, System 17, Country F Sort by Percent chronically absent ascending and read the 11th row. 11th is 14.12 percent, System 3, Country C Different countries. Answer: No. harshgoyal jainsaloni GMAT-Club-Forum-xuhj4arb.png

heyybhargav · Answer

For the first statement:
The number of chronically absent teachers in D is 6.07% of 11,362, i.e. ~ 689
The number of chronically absent teachers in G is 8.98% of 9,114, i.e. ~ 818
Here, clearly the number for D is less than that of G.

I don't understand why the answer for this statement is "Yes"

playthegame · Answer

Hello, if you sort the table by location you will see there are two lines for D and two for G.

So we will need to add both those lines together before we compare.

Hope this helps, good luck.

vedika.vyas · Answer

You have to sort by the location and add the percentage for both rows of D and G. 
The number of chronically absent teachers in D is
6.07% of 11,362 + 27.12% of 6642. Which comes up to ~2491

The number of chronically absent teachers in G
is 8.98% of 9,114 + 17.29% of 1608. Which comes up to ~ 1096

D>G

kop18 · Answer

I do not understand how we consider whether a line is +vly correlated or-vly correlated. In many questions I have seen that if majority line items are showing an upward trend then we consider the set to +ve correlated. Here to in the second statement - I can see that in 12 instance # of teachers and average day absent is correlated and 9 instances these are -vly correlated. It is only towards the end that one can see a major drop in this trend.

Can someone please explain with clarity and examples how to tackle such questions?

Can someone please explain with clarity and examples how to tackle such questions?

av722 · Answer

For the 21 school systems in the table, the number of chronically absent teachers in the school systems in Country D is greater than the number of chronically absent teachers in the school systems in Country G. 
did some estimation with numbers to make the calculation easier
D: 11000(.06)+7000(.3) = 2760
G: 2000(.2)+10,000(.1) = 1400

D>G, so  true

For the 21 school systems in the table, there is a positive correlation between the number of teachers and the average number of days the teachers were absent. 
as the number of teachers goes up, the average days absent shows no specific trend. as a result, there's no positive correlation.  false

The school system in the table with the median number of teachers is in the same country as the school system in the table with the median percent of chronically absent teachers. 
there's 21 teachers.
median will exist at (21+2)/2 = 11th teacher. sorting by number of teachers, median is F=4,991 teachers.
then sorting by percent of chronically absent teachers:
median is C=14.12%.
F not the same as C, so  false

KarishmaB · Answer

2 variables are positively correlated if they move in the same direction. When one increases, other increases too for the most part.

We can plot one curve for "Number of teachers" from smallest to greatest (sort by the number of teachers) - goes from 974 to 59,750.
Now when you plot the graph for "average days spent", does it go up from left to right? No it won't go up. It is going up and down at will as we can see from the data in the table. There is no consistent upward trend.

Plot the graph. Are they two positively correlated? Are they moving together? Number of teachers is rising (the table is sorted by number of teachers) but Absent days is all over the place.

I have made the graph but for some reason am unable to put it up. Will check with the mod and then put it up. Meanwhile you can try plotting it.

*Added the graph

Attachment:

Screenshot 2025-08-16 at 8.11.58 AM.png

gchandana · Answer

KarishmaB , but in exam conditions, plotting isn't feasible, right?
We know that if more than 50% of the data points increase/decrease in line with the first metric, we can determine the correlation.
But now, after looking at this question, I am worried about how to approach it without plotting, as it looks like the above condition alone isn't enough sometimes.

Could you share some insight on this?

kartickdey · Answer

Bunuel   KarishmaB 
Regarding Q2, I determine positive or negative relationship in the same way as you have mentioned. I do not draw any graph. 
In that way out of 20 changes, there 12 times positive relationship and 8 times negative relationship. so I clicked yes and the answer got wrong. Please guide me in learning the best way to determine the positive or negative relationship.

The table gives information about teacher absenteeism in 21 school

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Scool system	Location(country)	Number of teachers	Average days absent	Percent chronically absent
1	A	5,636	10.19	11.12
2	B	2,382	13.87	36.82
3	C	1,778	11.77	14.12
4	C	2,896	15.6	33.81
5	C	2,151	14.82	32.03
6	A	9,395	11.93	15.22
7	A	8,266	9.68	13.65
8	D	6,642	13.91	27.12
9	E	974	9.56	12.22
10	F	21,867	9.2	10.61
11	B	59,750	8.8	7.43
12	B	10,108	12.52	12.44
13	G	9,114	8.8	8.98
14	G	1,608	11.56	17.29
15	F	2,035	12.05	19.46
16	A	5,977	13.37	21.69
17	F	4,991	11.78	18.01
18	F	3,286	9.87	12.63
19	F	1,290	11	15.04
20	E	1,710	9.77	10.94
21	D	11,362	8.63	6.07

GMAT Graphs and Tables (G&T) Questions

The table gives information about teacher absenteeism in 21 school

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