Pitcher plants of genus Nepenthes are typically carnivorous, obtaining great deal of their nutrition from insects which become trapped in the pitcher, die, and decay. N. lowii, a pitcher plant from Borneo, produces a second kind of pitcher which attracts tree shrews (Tupaia montana), which give nutrients by defacating in the pitcher while they feed upon a substance secreted by the plant. Based upon measurements of 20 plants, Clarke et al. (2009) computed 95% confidence interval for the mean fraction of total leaf nitrogen in the plant species derived from tree shrews: 0.57 < u < 1.0.
a. Does this result imply that individual plants receive 57% and 100% of their leaf nitrogen from tree shrews? Explain.
b. Is the confidence interval meant to bracket the sample mean or the population mean?
c. Identify two values for the mean shrew fraction of total leaf nitrogen that the analysis suggests are among the most plausible.
d. Identify two values for the mean shrew fraction of total leaf nitrogen that the analysis suggests are less plausible.