Question

As a M.S. project, you are studying regeneration of eastern temperate forests at the VCU Rice Rivers Center. One year ago, you established a 5m x 5m (25 m²) plot, in which you completely clear-cut the vegetation and have been monitoring tree recruits since.

This year, while revisiting your plot, you recorded the following measurements for the tree seedlings that have resprouted since your experiment began.

0.63
0.59
0.73
0.61
0.53
0.57
0.54
0.65
0.52
0.77
0.72
0.39
0.44
1.29
0.49
0.34
0.88
0.7
0.44
0.93
0.54
0.53
0.77
0.52
0.29
0.93
0.5
0.7
0.64
0.59

*You will want to copy the dataset to your computer. Use Excel to calculate answers, and use the z table in the back of your book.  Be cautious in entering your answers; follow the directions for number of decimal places to include.*

      -The mean seedling height is: _________ (I got 0.63)(enter a number only, to two decimal points)
      -The standard deviation of your sample of seedlings is: __________ (I got 0.20) (enter a number only, to two decimal points)

      -If you measure an additional seedling to be 0.71 m tall, the z-score for that seedling is ____________(enter a number only, to two decimal points)

   -What proportion (between zero and one) of seedlings in your plot are shorter than 0.71 m?  ____________ (enter a number only, to four decimal places)

When faced with a problem or choice, humans can use two different strategies: "cognitive reflectivity," which results in slower responses and few mistakes, or "cognitive impulsivity," which results in quicker responses but also more mistakes. Depending on the individual, these two strategies are used differently. A pilot experiment was conducted on 22 right-handed individuals who were administered a cognitive reflectivity-impulsivity questionnaire, while recording voxel-based morphometry (regional gray matter density) in the ventral medial prefrontal cortex.

Based on the experimental design and the kind of data collected, which statistical test(s) should be used to determine whether there is an association between the cognitive strategy, cognitive reflectivity and the gray matter density of the ventral medial prefrontal cortex? Select all that apply!

		two sample t-test
		t-test of zero linear correlation
		z-test
		correlation coefficient (r)
		One-way ANOVA

Answer 1