If-else statement to count some variable - php

Question

I need some help to solved this algorithm problem with How a Person is popular in his city.
My situation
How the algorithm should work like
If a person "mark" has 500 friends in his city out of 500,000.
(500/500,000)*50,000 = 5
So 5 in 50,000 people Know him right.
But When friends count increase the 50,000 should decrease
If "sam" has 1000 friends then
(1000/500,000)*25000 = 5
So 5 in 25000 people know his name
Yes we could implement this in if/else condition
If so then i have to write 500 lines of code.
Is there another way to do this in PHP?
<?php
$totalfriends = 100;
$totali = 5000000;
$name = "Sam";
if ($totalfriends >= 100 && $totalfriends <= 499 ) {
$r = ($totalfriends/$totali)*50000;
echo round($r),' ',"in 50K People on City regonize this Profile";
}else if ($totalfriends >= 500 && $totalfriends <= 999) {
$r = ($totalfriends/$totali)*25000;
echo round($r),' ',"in 25K People on City know".$name;
}else{
echo "";
}
?>

Answer 1

is this what you are looking for?
foreach([100, 500, 543, 1000, 5000, 51000, 500000] as $my_friends)
echo '5 in '. getScoreOf($my_friends) . "<br>";
function getScoreOf($my_friends){
$of = 5;
$total = 5e5; //that's 500,000 ;)
$step = 100; //minimum step, so output is not "4604" but "4600"
$out_of = $total / $my_friends * $of;
return $out_of > $step? round($out_of / $step) * $step: round($out_of);
}
run it in sandbox
edit: solution merged with original code
<?php
$of = 5;
$totalfriends = 100;
$name = "Sam";
echo $of ." in ". getScoreOf($of, $totalfriends) ." people in city know ". $name;
function getScoreOf($of, $my_friends){
$total = 5e6; //that's 5,000,000 ;)
$step = 100; //minimum step, so output is not "4604" but "4600"
$out_of = $total / $my_friends * $of;
return $out_of > $step? round($out_of / $step) * $step: round($out_of);
}