A grouped frequency distribution of the scores obtained by students in a science quiz contains one missing frequency. The distribution is given below. It is known that the mode of the distribution is 34.
a. Class interval (scores): 0–10 10–20 20–30 30–40 40–50
Frequency: 4 9 12 k 8
(a) Find the value of k.
b. (b) After inserting the value of k, verify your answer by calculating the mode of the completed distribution, correct to two decimal places.