%c is our array of data. column 1 is whether there was a crash, and column 2 is the reason
c = {'Crash';'Crash';'Nothing';'Crash';'Crash';'Crash';'Nothing';'Nothing';'Crash';'Nothing'};
c(:,2) = {'Alcohol','Talking on Phone','Sleep','Talking on Phone',...
'Talking on Phone','Distracted','Talking on Phone','Ice','Car Malfunction','Talking on Phone'};
NumInc=sum(strcmp('Talking on Phone',c(:,2)) & strcmp('Crash',c(:,1))); %the only real important bit
sprintf('The number of people who were in a car crash because of talking on the phone is %d',NumInc)
disp(c)
This will count if both conditions are satisfied. The conditions are that the person was in a crash and the cause was talking on the phone. I've displaced the cell array c at the end so you can count for yourself that it is correct.
