install.packages("ggplot2") 
library(ggplot2)

install.packages("dplyr")
library(dplyr)

install.packages("rstatix")
library(rstatix)

#Insert the path to the file. The file should look like the HISTOGRAM.txt
his <- read.table("C:/.../HISTOGRAM.txt", fill=TRUE, header = T)

#It produces the histrogram graph
ggplot(his,aes(x=OADO_weighted_value, color=Faculty, fill=Faculty)) +
   geom_histogram(alpha=0.6, bins = 20) +  facet_wrap(~Faculty)

#It produces the Q-Q plot graph
his %>%
    ggplot(aes(sample = OADO_weighted_value)) +
    geom_qq() + geom_qq_line() +
    facet_wrap(~Faculty, scales = "free_y")


#It calculates the Shapiro-Wilk normality test
his %>%
    group_by(Faculty) %>%
    shapiro_test(OADO_weighted_value)