Find all files in the current directory and its subdirectories, calculate the size of each file and sum them up, then print each file size and the average size of all files.
find . -type f -exec du -sh {} + | awk ' {b[NR]=$0; s+=$1} END {for (i=1; i<=NR; i++) print b[i] " Scale(kb): " s/NR}'