Question

The time required for students to do a science experiment and the number of students is shown in the following grouped frequency distribution table. Show the information by a histogram and also by a frequency polygon.

Time required for experiment (minutes)	20 - 22	22 - 24	24 - 26	26 - 28	28 - 30	30 - 32
No. of students	8	16	22	18	14	12

Answer 1

Consider the following table

Class (Time required for experiment in minutes)	Class Mark	Frequency (Number of students)
20 - 22	21	8
22 - 24	23	16
24 - 26	25	22
26 - 28	27	18
28 - 30	29	14
30 - 32	31	12

The frequency polygon using the class mark and frequancy given in the above table as