26. The following is the frequency distribution table for the ages of the student
in a school. Answer the following questions :
Age (in yrs.)
No. of students
0_5
35
5–10
45
10-15
50
15-20
30
(a)
What is the class size of the class intervals ?
(b)
What is the upper limit of the fourth class interval ?
(c)
What is the lower class limit of the second class interval ?
(d)
What is the class mark of 0-5 ?
Answers
Answer:
1. Give five examples of data that you can collect from your day-to-day life.
Sol. 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.
2. Classify the data in Q. 1 above as primary or secondary data.
Sol. We have:
Primary data: (i), (ii) and (iii)
Secondary data: (iv) and (v)
EXERCISE 14.2
1. The blood groups of 30 students of Class VIII are recorded as follows:
A, B, O, O, AB, O, A, O, B, A, O, B, A, O, O,
A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O.
Represent this data in the form of a frequency distribution table. Which is the most common, and which is the rarest, blood group among these student?
Sol. A, B, O, O, AB, O, A, O, B, A, O, B, A, O, O, A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O.
From the above table, we have:
The most common blood group is O.
The rarest blood group is AB.
2. The distance (in km) of 40 engineers from their residence to their place of work were found as follows:
Construct a grouped frequency distribution table with class size 5 for the data given above taking the first interval as 0 – 5 (5 not included). What main features do you observe from this tabular representation?
Sol. The given distance (in km) are:
Here, the observation with minimum and maximum value are 2 and 32 respectively.
∵ The first class interval is 0 – 5,
∴ The classes are: 0 – 5, 5 – 10, 10 – 15, 15 – 20,
Step-by-step explanation:
A:-5-10
B:-15-20
C:-5-10
D:-35