(i)Find the class mark of the class 90-120. (ii)In a frequency distribution, the mid-value of the class is 10 and width of the class is 6. Find the lowe limit of the class. (iii)The width of each of the five continuous classes in a frequency distribution is 5 and lowe class limit of the lowest class is 10. What is the upper class limit of the highest class? (iv) The class marks of a frequency distribution are 15,20,25...... Find the class corresponding to the class mark 20. (v)In the class intervals 10-20, 20-30, find the class in which 20 is included.