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DerekLin
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In an exploratory study, researchers discovered a strong negative corr 18 Feb 2024, 04:45
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Strong negative correlation with wood density: Tree size Control for: Tree age
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35% (medium)

Question Stats:

73% (02:18) correct 27% (02:31) wrong based on 792 sessions

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­In an exploratory study, researchers discovered a strong negative correlation between tree size and wood density for mature red spruce trees that were all about the same age. However, for groups of trees in which some trees were significantly younger than others in the group, the exploratory study did not find any correlation between tree size and wood density. Furthermore, trees with a higher wood density are stronger, more flexible, and able to survive more severe environmental conditions (such as drought or ice) than trees with lower wood density. In a subsequent study, the researchers will investigate whether this same relationship between tree size and wood density applies to the Siberian spruce.

Based on the information in the passage, select for Strong negative correlation with wood density a factor that has a strong negative correlation with wood density for mature red spruce trees of the same age according to the exploratory study. For Control for, select a factor for which the information indicates the researchers in the subsequent study would need to control in order to determine whether the relationship between tree size and wood density identified in the exploratory study applies to the Siberian spruce. Make only two selections, one in each column.
Strong negative correlation with wood density Control for
Tree size
Wood strength
Wood flexibility
Tree age
The ability of trees to survive severe environmental conditions
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Strong negative correlation with wood density: Tree size Control for: Tree age
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Schools: IIM (A) ISB '24
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In an exploratory study, researchers discovered a strong negative corr 26 Feb 2024, 00:15
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Sharin my Experience with this question:

I took 3 minutes on this question and made the right selection of choices

The tricky part was to choose the second choice which is a control variable (tree age) for the successive investigative study on tree of Siberian spruce
DerekLin
­In an exploratory study, researchers discovered a strong negative correlation between tree size and wood density for mature red spruce trees that were all about the same age. However, for groups of trees in which some trees were significantly younger than others in the group, the exploratory study did not find any correlation between tree size and wood density. Furthermore, trees with a higher wood density are stronger, more flexible, and able to survive more severe environmental conditions (such as drought or ice) than trees with lower wood density. In a subsequent study, the researchers will investigate whether this same relationship between tree size and wood density applies to the Siberian spruce.

Based on the information in the passage, select for Strong negative correlation with wood density a factor that has a strong negative correlation with wood density for mature red spruce trees of the same age according to the exploratory study. For Control for, select a factor for which the information indicates the researchers in the subsequent study would need to control in order to determine whether the relationship between tree size and wood density identified in the exploratory study applies to the Siberian spruce. Make only two selections, one in each column.
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In an exploratory study, researchers discovered a strong negative corr 22 Jun 2024, 07:38
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Thanks, the question does give you a hint on how the age in one group played out or had no correlation for mature red spruce trees, interesting question, it took some time to read the question as the passage is wordy.

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In an exploratory study, researchers discovered a strong negative corr 30 Jun 2024, 18:38
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In an exploratory study, researchers discovered a strong negative correlation between tree size and wood density for mature red spruce trees that were all about the same age( control factor  something which needs to be kept same  ).­

This sentence reveals all. ­
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In an exploratory study, researchers discovered a strong negative corr 28 Jun 2025, 16:04
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First answer is found here: strong negative correlation between tree size and wood density

The second answer is not as straight forward, we need to look for the component that was different across the group of trees that were studied, that made a difference in the results: in this case, the age of the tree.

However, for groups of trees in which some trees were significantly younger than others in the group, the exploratory study did not find any correlation between tree size and wood density.

DerekLin
­In an exploratory study, researchers discovered a strong negative correlation between tree size and wood density for mature red spruce trees that were all about the same age. However, for groups of trees in which some trees were significantly younger than others in the group, the exploratory study did not find any correlation between tree size and wood density. Furthermore, trees with a higher wood density are stronger, more flexible, and able to survive more severe environmental conditions (such as drought or ice) than trees with lower wood density. In a subsequent study, the researchers will investigate whether this same relationship between tree size and wood density applies to the Siberian spruce.

Based on the information in the passage, select for Strong negative correlation with wood density a factor that has a strong negative correlation with wood density for mature red spruce trees of the same age according to the exploratory study. For Control for, select a factor for which the information indicates the researchers in the subsequent study would need to control in order to determine whether the relationship between tree size and wood density identified in the exploratory study applies to the Siberian spruce. Make only two selections, one in each column.
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