In order to find the highest and lowest marks, we have to arrange the marks in ascending order as follows:
39, 48, 56, 75, 76, 81, 84, 85, 90, 95
(i) Clearly, the highest mark is 95 and the lowest is 39.
(ii) The range of the marks obtained is: (95 – 39) = 56.
(iii) From the following data, we have
Mean marks = Sum of the marks/ Total number of students
Mean marks = (39 + 48 + 56 + 75 + 76 + 81 + 84 + 85 + 90 + 95) ÷ 10
= 729 ÷ 10
= 72.9.
Hence, the mean mark of the students is 72.9.