% 1) generate marks
marks = round(rand(30,11) * 100);
marks

% 2) marks of 4th student
marks(4, :)

% 3) average mark for lab2
lab2_av = mean(marks(:,2),1); % or equivalently lab2_av = sum(marks(:,2))/size(marks,1);
lab2_av

% 4) sum of lab marks for each student in vector
labs_sums = sum(marks(:, 1:10), 2);
labs_sums

% 5) calculate final marks
labs_prcnt = labs_sums/1000;
exam_prcnt = marks(:, 11)/100;
final_mark = (labs_prcnt*20)+(exam_prcnt*80);
final_mark

% 6) plot mark against student number
% it does not make sense to join the points on the graph
x = 1:30;
y = final_mark;
plot(x, y, 'x')