A biotechnology company models the number of active cells in

Question

https://gmatclub.com/forum/download/file.php?id=89925 A biotechnology company models the number of active cells in a laboratory culture during the first 24 hours after treatment. The graph shows the modeled number of active cells, in thousands, over time. Points A, B, C, D, E, and F correspond to hours 4, 8, 12, 16, 20, and 24, respectively. From each drop-down menu, select the option that creates the most accurate statement based on the information provided. For integer hours from 12 through 24, inclusive, the average number of active cells is approximately GRAPH_1_PLACEHOLDER the average for integer hours from 4 through 16, inclusive. The median of the numbers of active cells represented by points C through F is approximately GRAPH_2_PLACEHOLDER the median of the numbers represented by points A through D. GMAT-Club-Forum-aprshk17.png

Bunuel · Accepted Answer

https://gmatclub.com/forum/download/file.php?id=89925

A biotechnology company models the number of active cells in a laboratory culture during the first 24 hours after treatment. The graph shows the modeled number of active cells, in thousands, over time. Points A, B, C, D, E, and F correspond to hours 4, 8, 12, 16, 20, and 24, respectively.

From each drop-down menu, select the option that creates the most accurate statement based on the information provided.

For integer hours from 12 through 24, inclusive, the average number of active cells is approximately  GRAPH_1_PLACEHOLDER  the average for integer hours from 4 through 16, inclusive.

The median of the numbers of active cells represented by points C through F is approximately  GRAPH_2_PLACEHOLDER  the median of the numbers represented by points A through D.

Official Solution:

The graph shows three distinct stages in the number of active cells. From about hour 4 through hour 12, the curve is nearly flat at roughly 700–800 thousand cells. Between about hours 12 and 16, the number rises sharply. From about hour 17 through hour 24, the curve levels off again at roughly 2,400–2,500 thousand cells.

Points A through F mark selected values along this curve at 4-hour intervals.

Drop-down 1

Here, “integer hours from 4 through 16, inclusive” means the values at hours 4, 5, 6, ..., 16. There are 13 such values. The interval from hours 12 through 24 also contains 13 integer-hour values.

For hours 4 through 16, the first 9 values, from hours 4 through 12, are all close to about 700–800 thousand. We can treat their average as roughly 700 thousand.

The remaining 4 values, from hours 13 through 16, rise from about 1,200 thousand to about 2,300 thousand, giving an average of roughly 1,800 thousand.

So the overall average is approximately:

(9 * 700 + 4 * 1,800) / 13 ≈ 1,000 thousand

For hours 12 through 24, the first 5 values, from hours 12 through 16, cover the rising portion of the curve and average roughly 1,600 thousand. The remaining 8 values, from hours 17 through 24, are all close to about 2,500 thousand.

Thus, this average is approximately:

(5 * 1,600 + 8 * 2,500) / 13 ≈ 2,000 thousand

Therefore, the average from hours 12 through 24 is approximately  2 times  the average from hours 4 through 16.

Drop-down 2

This dropdown considers only the values represented by the labeled points.

For points A through D, the four values are A, B, C, and D. Since they increase from left to right, the median is the average of the two middle values, B and C.

From the graph, B is approximately 700 thousand and C is approximately 800 thousand. Thus, the median is approximately:

(700 + 800) / 2 = 750 thousand

For points C through F, the four values are C, D, E, and F. The two middle values are D and E.

From the graph, D is approximately 2,300 thousand and E is approximately 2,500 thousand. Thus, the median is approximately:

(2,300 + 2,500) / 2 = 2,400 thousand

Since 2,400 is a little more than 3 times 750, the best approximation is  3 times .

Correct answer:

Drop-down 1: "2 times"
Drop-down 2: "3 times"

hd29 · Answer

Portion C to D can be safely ignored for calculating both mean and median as it is included in both sides being compared.

After this we can see that both mean and median is 4 times the segment A to C for segment D to F.

A biotechnology company models the number of active cells in

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A biotechnology company models the number of active cells in

Prep Toolkit

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

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745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards