Data Set #1. Inside vs. Outside Leaves from a Dense Holly Tree (Bruce Grant and Itzick Vatnick - Widener University)
Below is a data set for stomata for leaves taken from the interior vs. the outside (south side) of the foliage of a large holly tree on Widener's campus
from the spring of 1999. The stomata were counted at 400x, and the students estimated the area of their field of view to be 0.152 mm^2.
|inside leaves||outside leaves|
t-test for unequal variances:
t = 2.718 (d.f. = 11)
for which t Critical one-tail = 1.796
and P(T<=t) one-tail = 0.010
The test shows that there is a
1 in a 100 chance of obtaining
this large a t-value at random;
therefore, the stomata density in the
sun is significantly higher
than in the shade.
click to enlarge...