Question 1. Give five examples of data that you can collect from your day-to-day life.
Solution: Following are five examples which are related to day-to-day life:
(i) Number of girl students in our class.
(ii) Number of computer sets in our computer-lab.
(iii) Telephone bills of our house for last two years.
(iv) Number of students appeared in an examination, obtained from newspapers.
(v) Number of female teachers in all the schools in a state obtained from the education department.
Question 2. Classify the data in Q. 1 above as primary or secondary data.
Solution: We have: Primary data: (i), (ii) and (iii) Secondary data: (iv) and (v)
PRESENTATION OF DATA
I . Every group into which the raw data is condensed is called a class-interval.
II . In each of these classes, the least number is called the lower class-limit and the greatest number is called upper class-limit.
III. The difference between the upper limit and the lower limit of a class is called its class size.
IV. The difference between the maximum value and the minimum value of the observation is called the range.
V. The class-mark of a class =