For 15 students at a secondary-school canteen, the following sales amounts arranged in ascending order of magnitude are observed: $10, 10, 12, 12, 12, 13, 14, 15, 19, 20, 25, 27,29, 30, 34. Determine...

For 15 students at a secondary-school canteen, the following sales amounts arranged in
ascending order of magnitude are observed: $10, 10, 12, 12, 12, 13, 14, 15, 19, 20, 25, 27,29, 30, 34.

             Determine the

(i)          mean

(ii)        median

(iii)       standard deviation for these sales amounts

(iv)       second decile
(v)         40th percentile point for these sales amounts