Grading Scale

Still a missing part, the averaging: numerical computations, in ksh/bash, can be done by including an expression by $(( )), like:

grade=$(( $grade1 + $grade2 ))

etc... it is faster to experiment than to describe it.

Example of what the instructor emailed me to assist. Will this help with the missing part. I did not understand how to apply it.
 
Below are tips to help you with this week's assignment.

This is how you would declare your variables:
declare -i GRADE1

This is how you would read in your grades from the keyboard:

 read -p "Please enter your first grade : " GRADE1
This is how you would average your grades:
((AVERAGE=($GRADE1 + $GRADE2 + $GRADE3)/3))

Ok, please check below and tell me if I am even close....

declare -iGrade1
read -p Please enter your first grade: Grade1 Grade1
if [ $Grade1 -ge 90 -a $Grade1 -le 100]
then
read -p Enter Grades Grades
echo A
then
declare -iGrade2
read -p Please enter your first grade: Grade2 Grade2
if [ $Grade2 -ge 89 -a $Grade2 -le 80]
then
read -p Enter Grades Grades
echo B
then
declare -iGrade3
read -p Please enter your first grade: Grade3 Grade3
if [ $Grade3 -ge 79- a $Grade3 -le 70]
then
read -p Enter Grades Grades
echo C
then
declare -iGrade4
read -p Please enter your first grade: Grade4 Grade4
if [ $Grade4 -ge 65-a $Grade4 -le 69]
then
read -p Enter Grades Grades
echo D
then
declare -iGrade5
read -p Please enter your first grade: Grade5 Grade5
if [ $Grade5 -ge 0 -a $Grade5 -le 64]
then
read -p Enter Grades Grades
echo F
fi
then
if       [[ GRADE1= A || GRADE2= B || GRADE3= C || GRADE4= D || GRADE5= F  ]]
then ((Average=($Grade1 + $Grade2 + $Grade3)/3))

I did not know this syntax:

((AVERAGE=($GRADE1 + $GRADE2 + $GRADE3)/3))

actually it works but it is equivalent to

AVERAGE=$((($GRADE1+$GRADE2+$GRADE3)/3))

which I prefer, see previous comment. I suggest you to open a terminal and test these commands interactively before putting all together in a script, you have already all the information.

No, you should first read GRADE1, then GRADE2 then GRADE3, without any if condition, then compute the average, then print A, B, C.. F according to the result of the average with the if conditions.
Notice that variables in Unix shell are case sensitive, so Grade1 and GRADE1 are different. Also make sure that you use ASCII quote characters " , I think you are using some typographic quote characters in your test, maybe from a word processor, that will not work if pasted into a script.

I am clueless when it comes to shell script. I posted an assignment for assistance but still did not get the understanding of your reply. For every question asked I go a question in reply. I posted what I had and still haven't gotten a reply. I have decided to find someone else who maybe able to do this for me. I am not interested in shell script because I'll never use it again after this class, it's just a requirement.

It is a useful skill and while you are probably stressed out, you would regret later why you didn't do just a few more hours of work.  Let me give you a few hints.  So read very carefully and I am sure if you try to apply yourself, you will not have any problem in doing it.  

I am assuming that you can use bash.  The way to check it is:
Issue the command
which bash

And it should simply return the path, may be /bin/bash.
If you don't have bash, you can try  which ksh, it should work with ksh also.

Modify the script with your favorite editor

The first line should say:
#!/bin/bash
If you don't have bash, you can try  which ksh, it should work with ksh also.

Now assume that total of points is zero.  This would help us to run the loop.
total=0

Run the following loop.  You know you can play with it by printing value --> echo $i    to see how values change in loop.

For mathematical conditions in bash and ksh you should use (( )) instead of [[ ]] pair.

for i in first second third
do
        read -p "Enter $i points " points
        total=$(( total + points ))
done

After this loop, total has the total of all points.  To get the average you need to divide it by three.

Please play with it, print values by using echo and see how it works.  Modify it to see the change in behavior.

average=$(( total / 3 ))

So far so good.  You can now print the value $average by using echo command.  Save it and run and see if it works without an error.

Conditions should work without a problem.  Actually in the if , elif loop sequence, it the first condition is satisfied, it would not check the rest.  This means you don't need to check with AND or OR.  It should be something like.

if (( average >= 90 ))
then
        grade=A
elif (( average >=80 ))  #We already know it is not 90 or above otherwise it would not check this condition
then
        grade=B
#Can put more conditions here
fi

Finally, simply print the grade by saying this
echo "Final grade is:  $grade"

Hope it helps.  Please play with it and learn it by modifying it.  Don't be afraid to get error messages.