## First part is unrelated to test answers
name <-c('Smith','Jones','Washington','Young','Edmunds','Carlie','Petitbon','Smyth')
major<-c('MATH','MATH','STAT','STAT','STAT','MATH','STAT','MATH')
t1grade<-c(78,82,66,95,88,93,95,84)
t1date<-c("2021-01-29","2021-01-29","2021-01-29","2021-01-30","2021-01-29","2021-01-27","2021-01-30","2021-01-29")
t2grade<-c(67,79,82,91,89,92,91,86)
t2date<-c("2021-02-18","2021-02-24","2021-02-24","2021-02-23","2021-02-24","2021-02-25","2021-02-22","2021-02-25")
coursegrade<-c('C','B','C','A','B+','A','A','B')
class_scores<-data.frame(name,major,t1grade,t1date,t2grade,t2date,coursegrade)
#########################################


## Possible answers for the free response question on Test 2, Spring 2026

# (a)
library(readr)
class_scores <- readr::read_csv(file="Z:/My_Documents/teaching/stat_220/classresults.csv", col_names = F)

#or

class_scores <- read.csv(file="Z:/My_Documents/teaching/stat_220/classresults.csv", header = F)
names(class_scores) <- c('name', 'major', 't1grade', 't1date', 't2grade', 't2date')

library(lubridate)

# (b)
class_scores %>%
mutate(
conv_t1date = ymd(t1date),
conv_t2date = ymd(t2date)
)
# or:
conv_t1date = ymd(t1date);
conv_t2date = ymd(t2date)


conv_t2date-conv_t1date

mean(today()-conv_t2date)

#(c)
str(class_scores)
# or
glimpse(class_scores)
#or
summary(class_scores)

#(d)
test_plot <- ggplot(class_scores,aes(x=coursegrade,color=major)) + geom_bar()
 library(gganimate)
 library(transformr)
 test_animation <- test_plot +
   transition_states(major) 
 
 animate(test_animation)