The monthly electricity bills (in ₹) for two school hostels over six months are recorded as:
Hostel X: 1200, 1220, 1250, 1230, 1210, 1240
Hostel Y: 1180, 1260, 1300, 1200, 1220, 1280
Which hostel’s bills show greater variation?
(a) Hostel X
(b) Both hostels have equal variation
(c) Variation cannot be compared for unequal means
(d) Hostel Y