Provide solution and explanation.

The following are the score of 40 students in a 70 item examination. 26 47 67 27 53 56 42 50 23 46 59 30 41 39 57 35 15 43 43 21 56 51 33 52 59 51 58 34 44 38 55 48 50 12 48 52 54 54 36 47 Determine the Mean.