Mean: The mean (average) of a set of numbers is calculated by dividing the sum of all the numbers by the count of numbers. Range: The range of a set of numbers is the difference between the largest and smallest numbers in the set. Explanation - Sum of the marks: 36+37+31+42+23+38+17+18+35+25+29+35=366 Number of students: 12 Mean = Total Sum ∕ Number of Students =366∕12=30.5 Range: Maximum marks: 42 Minimum marks: 17 Range = Maximum - Minimum =42−17=25 Difference between Mean and Range: Difference = Mean - Range =30.5−25=5.5 Thus, the correct answer is