Data for Exercise 7.77

Corn

Format

A data frame/tibble with 12 observations on three variables

new

corn yield with new meathod

standard

corn yield with standard method

differences

new minus standard

References

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

Examples


boxplot(Corn$differences)

qqnorm(Corn$differences)
qqline(Corn$differences)

shapiro.test(Corn$differences)
#> 
#> 	Shapiro-Wilk normality test
#> 
#> data:  Corn$differences
#> W = 0.92248, p-value = 0.3072
#> 
t.test(Corn$new, Corn$standard, paired = TRUE, alternative = "greater")
#> 
#> 	Paired t-test
#> 
#> data:  Corn$new and Corn$standard
#> t = 3.8308, df = 11, p-value = 0.001395
#> alternative hypothesis: true difference in means is greater than 0
#> 95 percent confidence interval:
#>  4.116803      Inf
#> sample estimates:
#> mean of the differences 
#>                    7.75 
#>