A survey recorded the daily pocket money (in ₹) of 28 students as follows:
Pocket money: 0 – 10 | 10 – 20 | 20 – 40 | 40 – 70 | 70 – 100
Frequency: 4 | 6 | 10 | 5 | 3
Find the mean daily pocket money of the students (correct to one decimal place).
(a) 32.1
(b) 34.3
(c) 33.6
(d) 30.0