There are too many mistakes in your own code, so I might as well rewrite it for you.
Let's stick to my jokes and share them with everyone.
[data, txt] = xlsread ('d: \ test.xlsx',' input');
N = size (data,1); Percentage of students
avg=mean(data(:，2:4)')； % data: student number, language, number, foreign language
Data = [data average];
data sort = round( 100 * data sort)/ 100； % Keep two decimal places
[DATA，ind]=sort(datasort(:，end)，“descend”)； Percentage ranked by average score
outdata=[datasort(ind，:)[ 1: 1:N]']； %[ 1: 1:N] is the ranking.
Xlswrite ('d: \ test.xlsx '，outdata，' output '，' B2 ')； % output results
outtxt=txt(ind，)；
Xlswrite('D:\Test.xlsx '，outtxt，' output '，' A2 ')； % output name
Titlename={' name',' student number',' language',' mathematics',' English',' average',' ranking'};
Xlswrite ('d: \ test.xlsx', title name,' output',' a1'); % output field name
It's easier to understand.