Calculating random numbers?

[john1704]

Hello everyone,

I have a problem that I need help with.

Alright, so I have an average. Everybody knows that the formula to find an average number is:

x = (a + b + c + d) / 4

x being the average.

Say I already have an average, like this:

95 = (a + b + c + d) / 4

How would I generate four random numbers added together, divided by four, to get an average that equals 95?

Thanks very much!

[future448]

There may be a better way but I think this works

// x = (a + b + c + d) / 4

// 4x = a + b + c + d 

$average = 95;

$x = $average * 4;

$a = rand(1, $x - 3);

$max_range = $x - $a - 2;

$b = rand(1, $max_range);

$max_range = $max_range - $b - 1;

$c = rand(1, $max_range);

$max_range = $max_range - $c;

$d = $max_range + 3;

//test it works?
if($average == ($a + $b + $c + $d)/4)  {

echo 'a = ' . $a . '<br />';
echo 'b = ' . $b . '<br />';
echo 'c = ' . $c . '<br />';
echo 'd = ' . $d . '<br />';

echo 'All good';


   }