I'm working on some php code and I'm stuck on how to fix it. The first for loop keep repeating and I don't know how

I'm working on some php code and I'm stuck on how to fix it.

$Numbers= array(20);

$Mean=0;

//these functions are called

getNumbers();

calMean();

NumbersaboveMean();

calMedian();

calMode();

Mode();

//this function gets the numbers from the user

function getNumbers()

{

$temp=0;

echo " Enter up to 10 float point numbers ";

for( $n=0; $n<20; $n++)

{

$Number[$n]=(float)readline('Enter a number: ');//gets the number from the user

}

//This arranges the numbers in order from least to greatest

for( $n=0; $n<20; $n++)

{

$temp=$Number[$n];

$Number[$n]=$Number[$n+1];

$Number[$n+1]=$temp;

}

}

//This function calculates the mean

function calMean()

{

for( $n=0; $n<20; $n++)

{

$sum=$sum+$Number[$n];

}

$Mean=$sum/(20);

echo "The mean of your numbers is " + $Mean;

}

// funciton determines how many numbers are above the mean

function NumbersaboveMean()

{

$track=0;

for($n=0;$n<20;$n++)

{

if($Number[$n]>$Mean)

{

$track++;

}

}

echo " There are " + $track + " numbers above the mean.";

}

//determines what the median is

function calMedian()

{

$median=Number[10];

echo "The median of your numbers is " + $median;

}

//this function determines what the mode is

function calMode()

{

$mode=0;

$count=0;

$count2=0;

$md2=0;

for($n=0;$n<18;$n++)

{

if($Number[$n]===$Number[$n+1])

{

$count2++;

}

if(count==count2)

{

$count=$count2;

$count2=0;

$md2=1;

}

else if(count

{

$mode=$Number[$n];

$count=$count2;

$count2=0;

}

}

}

//determines if there is 1 mode or more

function mode()

{

if(md2>0)

{

echo "There is more than 1 mode.";

}

else

{

echo "The mode is " + mode;

}

}

?>

The first for loop keep repeating and I don't know how to proceed