During a four-day period, a height measurement and a weight measuremen

Question

https://gmatclub.com/forum/download/file.php?mode=view&id=38613 During a four-day period, a height measurement and a weight measurement were recorded shortly after delivery for each baby born in a particular hospital. The 19 babies in the study were divided into two groups, Group A and Group B. The chart shows the length, in centimeters (cm), and weight, in kilograms (kg), for each of the 19 babies. Based on the given information, use the drop-down menus to most accurately complete the following statements. The correlation between length and weight for the babies in the study is GRAPH_1_PLACEHOLDER If a baby with weight less than 3.5 kg were selected at random, the probability that the baby would be a part of Group A is GRAPH_2_PLACEHOLDER ID: 100409 IR_IBN00867_img_001.png

GMATCoachBen · Accepted Answer

Short video solution here (1:06):

https://www.youtube.com/watch?v=9uPB7B1UUxU

ganand · Answer

To find the correlation, observe the overall trend rather than individual values. You have to oberve the overall direction of the given values. In the given example its clear that height and weight are strongly positively correlated.

Check the following link:

https://www.statisticshowto.com/directi ... sociation/

Hope it helps.

Sajjad1994 · Answer

Official Explanation

1. The correlation between length and weight for the babies in the study is:

Among all of the babies in the study, the graph shows that greater lengths tend to correspond to greater weights. This indicates a strongly positive correlation between length and weight.

The correct answer is strongly positive.

2. If a baby with weight less than 3.5 kg were selected at random, the probability that the baby would be a part of Group A is_____________.

In the graph there are 4 blue circles and 6 triangles below the horizontal line at 3.5 kg. This indicates that 10 babies in the study weighed less than 3.5 kg, and that of these 10, 4 were in Group A. Thus, the probability that the randomly selected baby was a part of Group A is 4/10=0.40.

The correct answer is 0.40.

KarishmaB · Answer

We see that there is certainly a positive correlation. The trend line is obvious and the data points are close to the trend line. There is only one option with positive correlation and that is "strongly positive". So that is correct. An r of 0.6 to 0.8 is considered "strong" and looking at the data, it does seem to be a case of strong correlation, not "weak" and not "very strong" either. But they don't ask us to make that call because we can't actually calculate r.

Here is a discussion on correlation: https://youtu.be/Zx-PysHlhGM

During a four-day period, a height measurement and a weight measuremen

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During a four-day period, a height measurement and a weight measuremen

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