How to add row values in matrix using a loop?

I have matrix A

A = [ 1 1 2 0.1;    
    2 2 3 0.02;
    3 3 4 0.05;
    4 4 5 0.3;
    5 2 6 0.5;
    6 2 7 0.4;
    7 7 8 0.2;
    8 3 9 0.9;
    9 4 10 1.3
   ];

I want to add row values like that using a loop..

X1 = A(1,4)
X2 = A(1,4)+A(2,4)
X3 = A(1,4)+A(2,4)+A(3,4)
X4 = A(1,4)+A(2,4)+A(3,4)+A(4,4)
X5 = A(1,4)+A(2,4)+A(5,4)
X6 = A(1,4)+A(2,4)+A(6,4)
X7 = A(1,4)+A(2,4)+A(6,4)+A(7,4)
X8 = A(1,4)+A(2,4)+A(3,4)+A(8,4)
X9 = A(1,4)+A(2,4)+A(3,4)+A(4,4)+A(4,9)

B= [ X1;    
     X2;
     X3;
     X4;
     X5;
     X6;
     X7;
     X8;
     X9;    
   ];

How can I do that? Any tips?

Many Thanks in advance

[Image Analyst]

There doesn't seem to be any rule for which elements of A you pick in getting the B's. It seems to follow a rule like you could say B = cumsum(A(:,4)) through X4 but then everything breaks down after X5 with indexes seeming to be chosen at random. What is the rule? Or are there just tons of typos in your indexes?

[Yuli Hartini]

I want a number will follow the lines of A (:, 1), and will cease in A (:, 2).

How can I do that?

[Walter Roberson]

According to that rule,

X7 = A(1,4)+A(2,4)+A(6,4)+A(7,4)

should be

X7 = A(1,4)+A(2,4)+A(3,4)+A(4,4)+A(5,4)+A(6,4)+A(7,4)

since you have 7 7 8 0.2 for that row.

I can see how you might be defining the other rows, but not that one.

[Yuli Hartini]

How about this: Number will follow the lines of A (:, 1), and will cease in A (:, 2). When A(:,2)=(A(:,3)+1)

How can I do that?

[Walter Roberson]

None of your examples have A(:,2)=(A(:,3)+1) . In some cases A(:,2)=(A(:,3)-1) .

Your proposed rule is not clear on what to do when the relationship between those two columns does not hold.