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 (link to dataset) 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:  (enter a number only, to two decimal points)
      -The standard deviation of your sample of seedlings is:  (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)

Answer 1

The mean seedling height is = 0.625667 ( Excel formula = AVERAGE(A2 : A31) )

The standard deviation of your sample of seedlings is = 0.201609 ( Excel formula = STDEV(A2 : A31) )

z-score for an additional seedling to be 0.71 m tall

The proportion (between zero and one) of seedlings in your plot are shorter than 0.71 m