The weekly wages (in Rs.) of 30 workers in a factory are `830, 835, 890, 810, 835, 836, 869, 845, 898, 890, 820, 860, 832, 833, 855, 845, 804, 808, 812, 840, 885, 835, 835, 836, 878, 840, 868, 890, 806, 840`. Using tally marks, make a frequency distribution table with class intervals `800 – 810, 810 – 820` and so on.