summarising grades by questions (tidy_

grade_summary.R

library(tidyverse)

# simulate data
n_students <-  50;
grades <- c(100,
            85,
            78,
            72,
            68,
            65,
            62,
            58,
            55,
            52
)
questions <- c(1,2,3,4)
sample_data = data_frame(g = sample(grades, n_students, replace=TRUE), q = sample(questions, n_students, replace=TRUE))

# summarise data
grade_summary <- sample_data %>%
  group_by(q) %>%
  summarise(mean_grade = mean(g),
            median_grade = median(g)) %>%
  arrange(q)

# look at data
head(grade_summary)