Rearrange matix in ascending order using one column as index!

Hallo! I have one matix with two columns where each value of column 1 correnponds to the value of the same row at column 2. I want to rearrange the matrix placing the items in column 1 in ascending order with its paired value of colymn 2.

example if i have a=[7 100;1 200;5 24,8;3 72] I want b=[1 200;3 72;5 24,8;7 100];

Answer 1

[KSSV]

a=[7 100;1 200;5 248;3 72]
b=[1 200;3 72;5 248;7 100] ;

[val,idx] = sort(a(:,1)) ;
b = a(idx,:)