Question (1): The following table gives the ages of 50 students in Biostatistics. (12 Points) class 01 - 10 frequency 5 11 - 20 10 A- 30 B 31-40 12 41-50 Total 8 50 1. Find the value of A and B. 2. Compute the mean for these grouped data. 3. Compute the standard deviation. 4. What is the percentage of measures are less than 21? 5. How many measures are greater than or equal to 31? 6. Estimate the total number of marks in the third class.