The table lists data on each of 7 hiking trails managed by a regional

Question

The table lists data on each of 7 hiking trails managed by a regional park authority. For each trail, the terrain type refers to the primary surface of the trail, the average hike time is the mean (arithmetic mean) number of minutes taken by hikers to complete it, the satisfaction score is the average (arithmetic mean) rating out of 100 reported by visitors, and the usage rank is the trail’s ranking based on total visitors, where a smaller number denotes higher usage.

Trail 
 Terrain type 
 Average hike time (min) 
 Satisfaction score 
 Usage rank 
 
  Aspen Loop 
 forest 
 92 
 83 
 3 
 
  Granite Path 
 rocky 
 105 
 91 
 2 
 
  Riverwalk 
 gravel 
 88 
 72 
 6 
 
  Summit Ridge 
 rocky 
 117 
 95 
 1 
 
  Willow Creek 
 forest 
 84 
 79 
 4 
 
  Sandy Dunes 
 sand 
 78 
 69 
 7 
 
  Canyon Bend 
 gravel 
 95 
 81 
 5

For each of the following statements about this data, select  Yes  if the statement can be inferred from the given information. Otherwise, select  No.

Bunuel · Accepted Answer

• Trails with rocky terrain have, on average, higher satisfaction scores than those with forest terrain.

Rocky trails (Granite Path 91, Summit Ridge 95) average 93.
Forest trails (Aspen Loop 83, Willow Creek 79) average 81.
Since 93 > 81, the average for rocky trails is higher.
Answer:  Yes

• No gravel trail ranks among the three most-used trails.

Gravel trails: Riverwalk (rank 6), Canyon Bend (rank 5).
Both ranks are greater than 3, so none are in the top three.
Answer:  Yes

• Among the trails with above-average hike times, the one with the lowest satisfaction score is also the least used overall.

Average hike time = (92 + 105 + 88 + 117 + 84 + 78 + 95) / 7 = 94.1.
Trails above average: Granite Path (105, 91), Summit Ridge (117, 95), Canyon Bend (95, 81).
The lowest satisfaction among these is Canyon Bend (81), whose usage rank is 5.
But Sandy Dunes has rank 7 (lower usage overall). Therefore, Canyon Bend is not the least used overall.

Answer:  No

I29-222

AdarshSambare · Answer

I.  Arrange Satisfaction score Tab. 
Clearly Rocky terrain on average have higher score then forest terrain, in fact they have the highest score

Answer: Yes

II.  Arrange Usage rank Tab.

Note: Given in question Low Usage rank means high number of visitor
Gravel lies in bottom 3

Answer: Yes

III.  Tricky one if you don't read it slowly. 
 Above-average hike times, Arrange Average hike time Tab. 
The lowest satisfaction score is either 5 or 3.
but overall least used rank is Sandy Dunes with rank 7

Answer: No

Dereno · Answer

Let’s answer the questions one by one :

Question 1 :  Trails with rocky terrain have, on average, higher satisfaction scores than those with forest terrain.

Trails that have   rocky terrain   are as follows with their satisfaction scores.

Granite Path ( Satisfaction score = 91 ) , Summit Ridge (Satisfaction score = 95).

Average should be roughly between 91 and 95. Exactly 93.

Trails that have   forest terrain   are as follows with their satisfaction scores.

Willow creek ( satisfaction score : 79) , Aspen Loop ( Satisfaction score : 83).

The average score is roughly between 79 and 83. Exactly 81.

Clearly, Rocky terrain average 93 is  GREATER  than the Forest terrain average 81. Hence,  YES .

Question 2 : No gravel trail ranks among the three most-used trails.

The three most used trails are : 1) Summit ridge ( rocky ) , 2) Granite path ( rocky) , 3) Aspen loop ( forest).

Thus, it’s clear that gravel trail don’t occupy the three most used ranks. Hence,  YES .

Question 3 : Among the trails with above-average hike times, the one with the lowest satisfaction score is also the least used overall.

First let’s find the average hike time for all the trails mentioned. Average hike time is between 92 and 95, as the values are not spread out.

Exact average hike time = (78+84+88+92+95+105+117)/7 is approx 94.5

Trails above the average are given with their satisfaction score, usage ranks :

Canyon Bend (SS : 81, UR : 5)

Granite path ( SS: 91, UR: 2)

Summit Ridge (SS : 95, UR 1).

The one with the lowest satisfaction score is Canyon Bend (81), with a usage rank of 5 - which is below the usage rank of 7. Hence,  NO .

HarshG7 · Answer

dont you think we should be looking from the ones "among the above average hike time". i spotted that and it immediately struck me that GMAT often tricks us with this and hence i only looked "among the above average hike time".

AdarshSambare · Answer

Hi  HarshG7 ,
Yes you are correct, we should be looking for "above average hike time".
But for that you need to calculate above average hike time right?
So, adding all the 7 values of Average hike time (min) and dividing it by 7.
You can use calculator and add
=> 78+84+88+92+95+105+117
=> 659/7
=> 94.5/ 95

So the Trails above the average are given with their satisfaction score, usage ranks :
Canyon Bend (SS : 81, UR : 5)

Granite path ( SS: 91, UR: 2)

Summit Ridge (SS : 95, UR 1)

The one with the lowest satisfaction score is Canyon Bend (81), with a usage rank of 5 but we have Sandy Dunes with worst Usage rank of 7
So the answer is  No ,

I hope the explanation was helpful

kovid231 · Answer

For the 3rd question. how are we taking averages of averages? isn't that something we shouldn't do considering this has been devised basis no. of minutes taken by hikers and we have different quantities of hikers. overall average could be very different from this average. please help explain this point to me.

Bunuel · Answer

•  Among the   trails    with above-average hike times, the one with the lowest satisfaction score is also the least used overall.

The statement is about the trails, not about all individual hikers. So we average the seven trail averages and compare each trail with that average.

egmat · Answer

Hi kovid231,

This is a sharp observation, and you're right about one thing:  if  the goal were the true average hike time across  all  hikers everywhere, then yes, you'd have to weight each trail's average by how many hikers walked it. Pooling raw hiker data and then taking a flat average of the seven trail numbers would give different results.

But that's not what the statement is doing. Look at the wording: it talks about  "trails with above-average hike times."  The thing being averaged here isn't hikers - it's  trails . Each trail contributes exactly one number (its own listed average hike time), and the benchmark is simply the  mean of those seven trail-level values . Each trail is weighted equally because the statement is sorting  trails , not blending  hikers .

So there are two different quantities, and only one of them is in play:

-  Average across all hikers  (a population figure) - this  would  need hiker counts to weight it. Your instinct is correct here.
-  Average of the seven trail averages  (a cutoff to classify trails as "above" or "below") - this treats each trail as one data point, so hiker counts are irrelevant.

The statement only needs the second one. You compute ( 92  +  105  +  88  +  117  +  84  +  78  +  95 ) /  7  ≈  94.1 , then pick out the trails reading above  94.1 : Granite Path (sat.  91 , rank  2 ), Summit Ridge (sat.  95 , rank  1 ), and Canyon Bend (sat.  81 , rank  5 ). No hiker weighting required - you're just ranking the seven listed numbers.

Now finish the statement - it lands on No

Within that above-average group, the  lowest satisfaction  is Canyon Bend ( 81 ), at usage rank  5 . The statement claims that trail is  also the least used overall . But the least used trail overall is  Sandy Dunes at rank 7  - and Sandy Dunes isn't even in the above-average group. So the lowest-satisfaction trail here is  not  the least used overall.

That's why the answer is  No  - exactly what Bunuel's solution above concludes. Your worry about averaging didn't actually change the answer; the simple mean of the seven trail values is the right cutoff, and once you apply it, the rank-7 mismatch settles it.

Answer: No

The table lists data on each of 7 hiking trails managed by a regional

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Trail	Terrain type	Average hike time (min)	Satisfaction score	Usage rank
Aspen Loop	forest	92	83	3
Granite Path	rocky	105	91	2
Riverwalk	gravel	88	72	6
Summit Ridge	rocky	117	95	1
Willow Creek	forest	84	79	4
Sandy Dunes	sand	78	69	7
Canyon Bend	gravel	95	81	5

Yes	No
		Trails with rocky terrain have, on average, higher satisfaction scores than those with forest terrain.
		No gravel trail ranks among the three most-used trails.
		Among the trails with above-average hike times, the one with the lowest satisfaction score is also the least used overall.

GMAT Graphs and Tables (G&T) Questions

The table lists data on each of 7 hiking trails managed by a regional

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