"Differentiation of Terminal Latewood Tracheids in Silver Fir Trees During Autumn," published online in the Annals of Botany in March 2005, describes research into the nature of the relationship between the trees' annual ring widths and the number of incompletely differentiated xylem cells per radial row.17 The latter serve as an indication of how long it takes until the tree becomes dormant for the winter.
a. Use software to regress number of incompletely differentiated cells on annual ring width. Report the regression equation and tell whether the relationship is positive or negative for the sample of 10 trees. b. Report the correlation and the P-value.
c. Choose the best summary from the following:
1. There is weak evidence of a weak relationship in the population.
2. There is weak evidence of a strong relationship in the population.
3. There is strong evidence of a weak relationship in the population.
4. There is strong evidence of a strong relationship in the population.
d. If a tree has very wide annual rings, what do you expect in terms of how late in the fall it becomes dormant?