Sorting Awk array by last name - arrays

Question

In my script, I start with a file of campaign contributors and anyone who donates a collective $500 is eligible for a contest. Anyone who meets that criteria I add to an array with an incrementing index to adjust the size as needed. Each index is formatted as outlined below, with the X's being a phone number. In the END portion of the script, I need to sort this array by last name($2) for printing. I've done some searching but come up empty handed. I'm not asking for someone to type the script for me, merely to point me in a better direction of search or offer advice. I need help sorting the array contestants as currently it will be filled properly with the string values the way I need them for the assignment.
Where v1,2, & 3 are the campaign contributions, I am using -F'[ :]' in my command to get both spaces and colons as field separators.
Input File lab4.data
Fname Lname:Phone__Number:v1:v2:v3
Mike Harrington:[phone]:250:100:175
Christian Dobbins:[phone]:155:90:201
Susan Dalsass:[phone]:250:60:50
Archie McNichol:[phone]:250:100:175
Jody Savage:[phone]:15:188:150
Guy Quigley:[phone]:250:100:175
Dan Savage:[phone]:450:300:275
Nancy McNeil:[phone]:250:80:75
John Goldenrod:[phone]:250:100:175
Chet Main:[phone]:50:95:135
Tom Savage:[phone]:250:168:200
Elizabeth Stachelin:[phone]:175:75:300
Array to hold anyone > $500, $8 is created and holds the value $5+$6+$7:
the array is initialized and filled in for loop given below
$8 = $5+$6+$7;
contestants[len++]
Loop to check add people to contestant array.
name and number are arrays that hold their respective values for later use.
for(i=0;i<=NR;i++)if(contrib[i]>500){contestants[len++]= name[i]" "number[i] }
Formatting of indexes(desired array values for contestant[len++]):
[0] Mike Harrington [phone]
[1] Archie McNichol [phone]
[2] Guy Quigley [phone]
[3] Dan Savage [phone]
[4] John Goldenrod [phone]
[5] Tom Savage [phone]
[6] Elizabeth Stachelin [phone]
Loop to print/check that array has been correctly filled(it is)
for (i=0; i <len; i++) {print contestants[i]}
Output:
Mike Harrington [phone]
Archie McNichol [phone]
Guy Quigley [phone]
Dan Savage [phone]
John Goldenrod [phone]
Tom Savage [phone]
Elizabeth Stachelin [phone]
Desired Final Output: Ignore formatting as it correctly displays in my terminal I just hard a hard time getting it all nice in here.
***FIRST QUARTERLY REPORT***
***CAMPAIGN 2004 CONTRIBUTIONS***
Name Phone Jan | Feb | Mar | Total Donated
Mike Harrington [phone] $ 250 $ 100 $ 175 $ 525
Christian Dobbins [phone] $ 155 $ 90 $ 201 $ 446
Susan Dalsass [phone] $ 250 $ 60 $ 50 $ 360
Archie McNichol [phone] $ 250 $ 100 $ 175 $ 525
Jody Savage [phone] $ 15 $ 188 $ 150 $ 353
Guy Quigley [phone] $ 250 $ 100 $ 175 $ 525
Dan Savage [phone] $ 450 $ 300 $ 275 $ 1025
Nancy McNeil [phone] $ 250 $ 80 $ 75 $ 405
John Goldenrod [phone] $ 250 $ 100 $ 175 $ 525
Chet Main [phone] $ 50 $ 95 $ 135 $ 280
Tom Savage [phone] $ 250 $ 168 $ 200 $ 618
Elizabeth Stachelin [phone] $ 175 $ 75 $ 300 $ 550
-----------------------------------------------------------------------------
SUMMARY
-----------------------------------------------------------------------------
The campaign received a total of $6137.00 for this quarter.
The average donation for the 12 contributors was $511.42.
The highest total contribution was $1025.00 made by Dan Savage.
***Thank you Dan Savage***
The following people donated over $500 to the campaign.
They are eligible for the quarterly drawing!!
Listed are their names(sorted by last names) and phone numbers.
John Goldenrod [phone]
Mike Harrington [phone]
Archie McNichol [phone]
Guy Quigley [phone]
Dan Savage [phone]
Tom Savage [phone]
Elizabeth Stachelin [phone]
Thank you all for your continued support!!

Answer 1

Using gawk, this is straightforward to do with the in-built sort functions, e.g.
BEGIN {
data["Jane Doe [phone]"] = 600;
data["Fred Adams [phone]"] = 800;
data["John Smith [phone]"] = 900;
exit;
}
END {
for (i in data) {
split(i,x," ")
data1[x[2] " " x[1] " " x[3] " " x[4]] = i;
}
asorti(data1,sdata1);
for (i in sdata1) {
print data1[sdata1[i]],"\t",data[data1[sdata1[i]]];
}
}
... which produces:
Fred Adams [phone] 800
Jane Doe [phone] 600
John Smith [phone] 900
In plain awk, the same result can be achieved by writing the array indices to a file, sorting that file and then reading the file back using getline.

Answer 2

The way to approach this is to produce the pre-SUMMARY output as you read the data so you don't need to store all of your data in an array, just the people who contributed more than $500 and just insert them into the array in the desired order using an insertion sort algorithm.
You would do it something like this:
awk -F':' '
NR==1 {
print "header stuff"
next
}
{
tot = $3 + $4 + $5
printf "%-20s%10s $%5s $%5s $%5s $%5s\n", $1, $2, $3, $4, $5, tot
}
tot > 500 {
split($1,name,/ /)
surname = name[2]
numContribs++
# insertion sort, check the algorithm:
for (i=1; i<=numContribs; i++) {
if (surname > surnames[i]) {
for (j=numContribs; j>i; j--) {
surnames[j+1] = surnames[j]
contribs[j+1] = contribs[j]
}
surnames[i] = surname
contribs[i] = $1 " " $2
break
}
}
}
END {
print "SUMMARY and text below it and then the list of $500+ contributors:"
for (i=1; i<=numContribs; i++) {
print contribs[i]
}
}
' lab4.data
The above is not a fully functional program. It's just intended to show you the right approach per your request.