The table below shows the duration (in minutes) taken by 100 students to solve a particular Mathematics question in an examination. Duration (minutes) Number of students 10 but less than 15 6 15 but less than 20 25 20 but less than 25 45 25 but less than 30 18 30 but less than 35 6 [a) Calculate the percentage of students who take less than 30 minutes to solve the Mathematics question. (2 marks) (b) Calculate the sample mean and standard deviation. (8 marks) Calculate median, (4 marks) (d) Draw the histogram on a graph paper and estimate the mode. (6 marks)