I am writing an exercise in RMarkdown (usign knitr in RStudio) which includes one numeric question and one single-choice question. Could you please help me produce the correct code that allows the activity to be displayed in Moodle, if possible? The numeric question requires entering the correlation coefficient (whose correct answer is “corr1” in the code below), and the single-choice question requires selecting the graph that represents the data (with “grafico1” being the correct answer).

library(ggplot2)
Concentration = c(7.1,82.9)
r.sq  = 0
while (r.sq <0.85) {
x = runif(33, min(Concentration),max(Concentration))
b = runif(1,-3,3)+rnorm(33,0,0.25)
a = ifelse(max(b)<0, -min(b)*max(x),0)
data = data.frame(Concentration = round(x,2), Reaction_time = round(a+b*x,2))
z = lm(data$Reaction_time~data$Concentration)
summa = summary(z)
r.sq = summa$r.squared
}
corr = round(cor(data$Concentration,data$Reaction_time),2)

corr1 = corr
r.sq  = 0
while (r.sq <0.85 | abs(corr1)<abs(corr)) {
x = runif(33, min(Concentration),max(Concentration))
b = runif(1,-3,3)+rnorm(33,0,0.25)
a = ifelse(max(b)<0, -min(b)*max(x),0)
data1 = data.frame(Concentration = round(x,2), Reaction_time = round(a+b*x,2))
z = lm(data1$Reaction_time~data1$Concentration)
corr1 =  round(cor(data1$Concentration,data1$Reaction_time),2)
summa = summary(z)
r.sq = summa$r.squared
}

corr2 = corr
r.sq  = 0
while (r.sq <0.85 | abs(corr2)<abs(corr)) {
x = runif(33, min(Concentration),max(Concentration))
b = runif(1,-3,3)+rnorm(33,0,0.25)
a = ifelse(max(b)<0, -min(b)*max(x),0)
data2 = data.frame(Concentration = round(x,2), Reaction_time = round(a+b*x,2))
z = lm(data2$Reaction_time~data2$Concentration)
corr2 =  round(cor(data2$Concentration,data2$Reaction_time),2)
summa = summary(z)
r.sq = summa$r.squared
}

corr3 = corr
r.sq  = 0
while (r.sq <0.85 | abs(corr3)<abs(corr)) {
x = runif(33, min(Concentration),max(Concentration))
b = runif(1,-3,3)+rnorm(33,0,0.25)
a = ifelse(max(b)<0, -min(b)*max(x),0)
data3 = data.frame(Concentration = round(x,2), Reaction_time = round(a+b*x,2))
z = lm(data3$Reaction_time~data3$Concentration)
corr3 =  round(cor(data3$Concentration,data3$Reaction_time),2)
summa = summary(z)
r.sq = summa$r.squared
}

write.csv(data,'concentration_vs_rxtime_q2.csv', row.names = FALSE)

p1 = ggplot(data, aes(x=Concentration, y=Reaction_time)) + geom_point()
p2 = ggplot(data1, aes(x=Concentration, y=Reaction_time)) + geom_point()
p3 = ggplot(data2, aes(x=Concentration, y=Reaction_time)) + geom_point()
p4 = ggplot(data3, aes(x=Concentration, y=Reaction_time)) + geom_point()

png('grafico1.png', width=380, height=248, units='px', pointsize=12)
p1
dev.off()

png('grafico2.png', width=380, height=248, units='px', pointsize=12)
p2
dev.off()

png('grafico3.png', width=380, height=248, units='px', pointsize=12)
p3
dev.off()

png('grafico4.png', width=380, height=248, units='px', pointsize=12)
p4
dev.off()

This code does not work in Moodle since the chart options do not have checkboxes available for selecting the correct answer.

Determine the correlation coefficinet:
##ANSWER1##


Choose the right plot for data:
1. ![](grafico1.png)  
2. ![](grafico2.png)  
3. ![](grafico3.png)  
4. ![](grafico4.png)

Meta-information
================
extype: cloze
exclozetype: num|schoice
exsolution: `r corr1`|1000
exname: mod10_q1