Charles Darwin's study of cross-fertilized and self-fertilized plants

Data for Exercise 7.62

Darwin

Format

A data frame/tibble with 15 observations on three variables

pot

number of pot

cross

height of plant (in inches) after a fixed period of time when cross-fertilized

self

height of plant (in inches) after a fixed period of time when self-fertilized

Source

Darwin, C. (1876) The Effect of Cross- and Self-Fertilization in the Vegetable Kingdom, 2nd edition, London.

References

Kitchens, L. J. (2003) Basic Statistics and Data Analysis. Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.

Examples

differ <- Darwin$cross - Darwin$self
qqnorm(differ)
qqline(differ)

shapiro.test(differ)
#> 
#> 	Shapiro-Wilk normality test
#> 
#> data:  differ
#> W = 0.90079, p-value = 0.09785
#> 
wilcox.test(Darwin$cross, Darwin$self, paired = TRUE)
#> 
#> 	Wilcoxon signed rank exact test
#> 
#> data:  Darwin$cross and Darwin$self
#> V = 96, p-value = 0.04126
#> alternative hypothesis: true location shift is not equal to 0
#> 
rm(differ)