ANS:

%open file for reading
fid = fopen('dataIn.txt');
d = textscan(fid, '%s %s %u', 'headerLines', 1);
fclose(fid);

%write out data
fid = fopen('dataOut.txt', 'w');
fprintf(fid, '%s %s %s\n', 'Age',  'First_Name', 'Last_Name', '');
for i=1:length(d{1})
    fprintf(fid, '%u %s %s\n', d{3}(i), d{1}{i}, d{2}{i});
end
fclose(fid);