People are mailing more and more packages these days and you
Solution
x=c(1,2,3,4)
 y=c(0.4,0.3,0.2,0.1)
 i=1
 z=array(dim=2)
 for(i in 1:1000)
 {
 z[i]=sample(x,2, replace = FALSE, prob = y)
 i=i+1
 }
 Mean=mean(z)
 Mean
 freq=data.frame(table(z))
 freq
 Probability=freq$Freq/sum(freq$Freq)
 Probability
 data=cbind(table(z),Probability)
 data
 r=array(dim=1)
 i=1
 for( i in 1:1000)
 {
 r[i]=sample(x,1, replace = FALSE, prob = y)-sample(x,1, replace = FALSE, prob = y)
 i=i+1
 }
 freq1=data.frame(table(r))
 freq1
 Probability1=freq1$Freq/sum(freq1$Freq)
 Probability1
 data1=cbind(table(r),Probability1)
 data1
The R code is provided it will give you the Following results
Probability ditrubution of Mean(X bar)
 1 393 0.393
 2 306 0.306
 3 204 0.204
 4 97 0.097
Probability Distribution of R
Probability1
 -3 26 0.026
 -2 95 0.095
 -1 210 0.210
 0 313 0.313
 1 197 0.197
 2 115 0.115
 3 44 0.044

