The first, freq, stands for a pipe that counts the frequency of words in stdin and outputs a list of the words, in decreasing order of frequency, with each output line consisting of a word, some white space, and a number. Try to get the numbers right-justified if you can. You'll need either sed or awk.
The second, avgsize, stands for a pipe (or however you choose to do it) that takes a directory name as an argument and computes the average number of bytes in non-directory files in that directory. For example, if the "ls -l" command gave the output
total 52
drwxr-xr-x 7 sbloch system 1024 Nov 21 1996 examples
drwxr-xr-x 2 sbloch system 512 Oct 12 1995 fall94
drwxr-xr-x 3 sbloch system 512 Sep 4 1996 fall95
drwxr--r-- 3 sbloch system 512 Aug 26 14:34 fall96
-rw-r--r-- 1 sbloch system 4865 Oct 7 09:18 hw2.html
-rw-r--r-- 1 sbloch system 4865 Oct 7 09:18 index.html
drwxr-xr-x 2 sbloch system 1024 Sep 12 11:54 syllabus
-rw-r--r-- 2 sbloch users 11812 Sep 12 11:54 syllabus.dvi
-rw-r--r-- 2 sbloch users 10418 Sep 12 11:53 syllabus.tex
drwx------ 2 sbloch system 512 Nov 9 1995 test
-rw-r--r-- 1 sbloch system 13070 Aug 8 1994 unix.editorial
then the output would be 9006 (i.e. (4865+4865+11812+10418+13070)/5).
You'll probably need awk; if you put your awk program into a separate
file, please turn in that file along with your alias command that
invokes it.