Is it ok now??
Code:
BEGIN{ print "Name Test1 Test2 Test3 Average Grade"}
{avg=($2+$3+$4)/3;avgtest1+=$2
avgtest2+=$3
avgtest3+=$4
if (avg >= 90 && avg < 100) grade="A"
else if (avg >= 80 && avg < 89) grade="B"
else if (avg >= 70 && avg < 79) grade="C"
else if (avg >= 60 && avg <69) grade="D"
else grade="F"
printf("%-8s%-8d%-8d%-8d%-8d%-8s\n",$1,$2,$3,$4,avg,grade)}
END{
printf "Average%-8d%-8d%-8d\n",avgtest1/NR,avgtest2/NR,avgtest3/NR}