The marks obtained by 45 students in a weekly mathematics quiz are listed below:
73, 48, 36, 90, 59, 62, 28, 15, 44, 55,
68, 77, 83, 41, 39, 24, 31, 52, 67, 70,
12, 49, 58, 64, 79, 86, 91, 18, 34, 27,
46, 53, 60, 74, 80, 82, 88, 95, 21, 30,
38, 42, 50, 57, 65
a. (i) Arrange the data into the following unequal class intervals and prepare a grouped frequency table:
0–20,20–30,30–50,50–70,70–100
b. (ii) For every class, calculate the frequency density.
c. (iii) On graph paper, draw a histogram for the distribution you have prepared.
d. (iv) Using your histogram, state the score range in which the marks are most densely concentrated per mark of the interval.