2erwtima.php

<?php
$username = "root";
$password = "";
$hostname = "localhost"; 

//connection to the database
$con = mysql_connect($hostname, $username, $password)
 or die("Unable to connect to MySQL");

//select a database to work with
$selected = mysql_select_db("grades_db",$con)
  or die("Could not select examples");

//execute the SQL query and return records
$result = mysql_query("SELECT Name,Surname,Grade FROM grades ORDER BY Grade");
$max = mysql_query("SELECT MAX( Grade )FROM grades");
$min = mysql_query("SELECT MIN( Grade )FROM grades");
$avg = mysql_query("SELECT AVG( Grade )FROM grades");


//fetch tha data from the database
while ($row = mysql_fetch_array($result)) {
    printf("%s %s %s %s %s </br>", $row["Name"], $row["Surname"], $row["Grade"] - $max, $row["Grade"] - $min, $row["Grade"] - $avg);
}
//close the connection
mysql_close($con);
?>