The graph provides data on weekly reaction times and resulting energy

Question

https://gmatclub.com/forum/download/file.php?id=85802 The graph provides data on weekly reaction times and resulting energy yields from 32 trials carried out by four research labs in the Andean Valley in 2022. Each lab conducted eight trials, and for every trial both the reaction time (in hours) and the resulting energy yield (in kilojoules) were recorded. Select from each drop-down menu the option that creates the most accurate statement based on the information provided. The range of the recorded energy yields was greatest for Lab GRAPH_1_PLACEHOLDER . The median reported reaction time for all trials across the four labs was GRAPH_2_PLACEHOLDER the median reported reaction time for all trials across the three labs excluding Lab D. GMAT-Club-Forum-d7i984pu.png

Bunuel · Accepted Answer

Drop-down 1:

The range of a data set is the maximum value minus the minimum value.

From the graph, the lowest yield is 260 and the highest yield is 1400, both from Lab D. Since both extremes belong to Lab D, Lab D has the greatest range.

Correct answer:  Lab D

Drop-down 2:

The median is the middle value of a data set in ascending order, or the average of the two middle values if the total number is even.

Across all 32 trials, the median is the average of the 16th and 17th values: (4 + 5)/2 = 4.5.

Across the 24 trials excluding Lab D, the median is the average of the 12th and 13th values: (4 + 5)/2 = 4.5.

Thus, the two medians are the same.

Correct answer:  the same as

I29-160

bb · Answer

Thank you!

Is it part of the challenge to not have an idea what could possibly have reaction time and energy yields together?

Just seems like two very unrelated items 😂

Bunuel · Answer

The specific connection between reaction time and energy yield isn’t essential for this question, but it’s not unrealistic either, many chemical reactions do release energy, so the two quantities can reasonably be considered together.

findingmyself · Answer

Range of recorded energy yield:   as it has one of the lowest values and the highest values among recorded ene    rgy yi  elds

The median reported reaction time for all trials across the four labs was the median reported reaction time for all trials across the three labs excluding Lab D.
 
  Median time for all 4 labs together is middle point of 16th and 17th readings which is 4.5 (4+5)/2  
  Total values 24 without D,   Median is middle point of 12th and 13th value which is again 4.5 since values are 4 and 5

Souradeep17 · Answer

The Highest difference between the highest Energy Yield and lowest is for Lab D

For median: There are 32 observation,2 The median should be 16 and 17 observations which is for 4 and 5 hours so the median is (4+5)/2=4.5

Now the median without D , the number of observations will be 24. 
The median should be 12th and 13th obs /2
which again comes to 4 and 5 hrs so the median will be (4+5)/2=4.5 Hence the median will remain same

Elite097 · Answer

The highest difference between the highest Energy Yield and lowest energy yield is for Lab D

For 32 observations median is between 16th and 17th observation which js 4.5
And without lab D, median for 24 observations is between 12th and 13 th observation which is also 4.5 hence same median

fugaquasi · Answer

Im a bit bad with graphs so this is how i did this one:

Q1
For a question asking range upon scanning the lowest values i can see lab A and lab D have the lowest values, a cursory glace also shows that lab A and lab D have the highest values but lab D's highest values is higher than Lab A's, Since they have the same lowest value, this means range of Lab D is the greatest.

=> Lab D

Q2

My reasoning here was to use no math at all, but to estimate.

For each week I assume what would happen to the median should i remove the result of Lab D, the results would be:

1: Lower median
2: Higher median
3: About the same
4: About the same
5: Higher Median
6: Much Lower Median
7: Higher Median

Hence i can see that the reults sorta cancel each other out, meaning the overall median would be about the same.

AbhishekP220108 · Answer

For 1
By just looking at the graph we can identify that Lab D and Lab A has same minimum level, however, when we look at higher value, Lab D wins and the range of highest Energy Yield and lowest energy yield is for Lab D

For 2
There are 32 observations and median value is avg of 16th and 17th observation which is 4.5
and by counting without lab D, median for the 24 observations is avg of 12th and 13th observation which is same as 32 observations i.e 4.5 hence median is same

Dereno · Answer

Question 1:

The range of the recorded energy yields was greatest for Lab

The approximate highest and lowest range values for the labs are as follows:

Lab A= (1380-220) = 1160.

Lab B = (1220 - 250) = 970.

Lab C = (1380-410) = 970.

Lab D = (1400 - 210) = 1190.

The range for lab D is the HIGHEST.

Question 2:

The median reported reaction time for all trials across the four labs was. (     Select: less than/ the same as/ more than     ). the median reported reaction time for all trials across the three labs excluding Lab D.

The median reported reaction time for all trials across 4 labs = (4+5)/2 = 4.5

If we remove the 8 values of lab D, then we get 32-8 = 24 values.

The median of the 24 values = (12th value + 13th value)/2 = (4+5)/2 = 4.5 .

Hence, BOTH these values are  same .

sunshineeee · Answer

Across the 24 trials excluding Lab D, the median is the average of the 12th and 13th values: (4 + 5)/2 = 4.5.
  
I did not understand how to spot the 12th and 13th values as 4 and 5. I thought the 3 and 4 as the 12th and 13th? Please kindly explain. Thanks

Bunuel · Answer

Excluding Lab D, you have 24 reaction times from Labs A, B, and C. Each of these labs has one trial at 1, 2, 3, 4, 5, 6, 7, 8, so you have three 1s, three 2s, three 3s, three 4s, etc.

So in the sorted list, positions 10, 11, 12 are all 4, and positions 13, 14, 15 are all 5. That makes the 12th value 4 and the 13th value 5.

sunshineeee · Answer

Got it, Thank you  Bunuel !

The graph provides data on weekly reaction times and resulting energy

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Graphs and Tables (G&T) Questions

The graph provides data on weekly reaction times and resulting energy

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards