In 1876, Charles Darwin had his book, The Effect of Cross and Self-Fertilization in the Vegetable Kingdom, published. Darwin planted two seeds, one obtained by crossfertilization and the other by auto-fertilization in two opposite but separate locations of a pot. Self-fertilization, also called autogamy or selfing, is the fertilization of a plant with its own pollen. Cross-fertilization, or allogamy, is the fertilization with pollen of another plant, usually of the same species. Darwin recorded the plantsâ€™ heights in inches. The data frame Fertilize from the PASWR package contains the data from this experiment.
(a) Are the samples independent or paired?
(b) Should normality be assumed?
(c) Do the more appropriate test to decide if significance differences exist between the median heights of the plants with regard to fertilization methods.