PHP Result not the Same as in Excel Despite Using the Same Formula

I have the following code in PHP:

//Declare User Value
$b9 = 3992;
$b10 = 0;
$b11 = 2;
$b12 = 0;
$b13 = 0;
$b14 = 35;
$b15 = 1;

//Declare Co-efficiant
$c9 = 0.10714;
$c10 = 183.272;
$c11 = 135.047;
$c12 = 348.672;
$c13 = 43.7136;
$c14 = 12.2912;
$c15 = 43.1313;
$c16 = -259.268;

$totalOne = +$c16+$c9*$b9+$c10*$b10+$c11*$b11+$c12*$b12+$c13*$b13+$c14*$b14+$c15*$b15;

echo '</p>>>'.$totalOne.'<<</p>';

And it outputs:

911.85218<<

There are the same values and formulas in an Excel sheet and it shows the following as a value: 911.8607208

I understand that it's very near, but not the same. Can you please help in obtaining the same result in my PHP Script as the one output in the Excel?

Thanks!