Solver Compute Mean, Median and Standard Deviation of a set of numbers

Source code of 'Compute Mean, Median and Standard Deviation of a set of numbers'

This Solver (Compute Mean, Median and Standard Deviation of a set of numbers) was created by by Shruti_Mishra(0)

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About Shruti_Mishra: I am a maths graduate from India and am currently persuing masters in Operations Research.

==section input
To compute Mean, Median and Standard Deviation, enter the comma separated list of numbers here: *[input series=1,2,3].

==section solution
perl

@aseries = split(',',$series);
$sum += $_ foreach @aseries ;
$n = @aseries;

if($n>0)
{
 $mean = $sum/$n;
 print "<a href='mean.lesson'>Mean:</a> The <a href='mean.lesson'>mean</a> of a series can be calculated by dividing the sum of the series by the number of elements in the series. In this case, the sum of the series is $sum and the number of elements in the series is $n. The <a href='mean.lesson'>mean</a> is thus $sum/$n = $mean. ";

print "<a href='median.lesson'>Median:</a> The <a href='median.lesson'>median</a> of a series is the element which is in the middle of the series when arranged in ascending/descending order. In case there are an even number of elements in the series, the median is the mean of the two middle numbers. In this case the median is thus: ";

for ($outer = $n - 1; $outer > 0; $outer--) 
 {
 for ($inner = 0; $inner < $outer; $inner++) 
 {
 if ($aseries[$inner] > $aseries[$inner + 1]) 
 {
 $temp = $aseries[$inner];
 $aseries[$inner] = $aseries[$inner + 1]; 
 $aseries[$inner + 1] = $temp; 
 } 
 }
 }
 if($n%2 == 0)
 {
 $median1 = $aseries[$n/2 - 1];
 $median2 = $aseries[($n+2)/2 - 1];
 $median = ($median1+$median2)/2;
 print "$median. ";
 }
 else
 {
 $median = $aseries[($n+1)/2 - 1];
 print "$median. ";
 }
 
 print "<a href='std_dev.lesson'>Standard Deviation:</a> The S.D. of a series is a measure of the variability of the elements with respect to the mean of the series. The formula for calculating the standard deviation is: 
<center>
{{{sigma=sqrt((sum((x[i] - mean)^2,1,n))/n)}}}
</center>
 In this case, the standard deviation is:";
$sd = 0;

for ($i = 0; $i < $n; $i++)
 {
 $sd = $sd + ($aseries[$i] - $mean)**2;
 }
 $sd = $sd/$n;
 $sd = $sd**0.5;
 $sd = sprintf("%.3f", $sd);
 print "$sd.";
}
else
{
 print "Insufficient/wrong input";
}

==section output
mean
==section check
 series=2 mean=2