Haryana State Board HBSE 7th Class Maths Solutions Chapter 3 Data Handling Ex 3.2 Textbook Exercise Questions and Answers.
Haryana Board 7th Class Maths Solutions Chapter 3 Data Handling Exercise 3.2
Question 1.
The scores in mathematics test (out of 25) of 15 students is as follows :
19.25.23.20.9.20.15.10.5.16.25.20.24, 12,20.
Find the mode and median of this data. Are they same ?
Solution:
We arrange the data in ascending order, we get,
5.9.10.12.15.16.19.20.20.20.20. 25, 25.
Mode of this data is 20 because it occurs 4 times more than frequently than other observations.
Now, Median is the middle observation.
Therefore, 20 is the median.
Yes, Mode and Median are same.
Question 2.
The runs scored in a cricket match by 11 players is as follows :
6,15,120,50,100,80,10,15,8,10,10.
Find the mean, mode and median of this data. Are the three same ?
Solution:
Mean = \(\frac{Sum of the scores}{No. of players}\)
= \(\frac{424}{11}\) = 38.5454 = 38.55
We arrange the data in ascending order, we get 6, 8, 10, 10,10, 15, 15, 50, 80, 100, 120.
∴ Mode of this data is 10 because it occurs three times more than other observations.
Now, Median is the middle observation.
Therefore 15 is the median.
∴ Mean, Mode and Median are not same.
Question 3.
The weights (in kg.) of 15 students of a class are :
38,42,35,37,45,50,32,43,43,40,36,38, 43,38,47.
(i) Find the mode and median of this data.
(ii) Is there more than one mode ?
Solution:
We arrange the data in ascending order, we get,
32,35,36, 37, 38, 38,38, 40,42,43,43,43, 45, 47, 50.
(i) Mode of this data is 38 and 43 because both occur three times more than- other observations.
Now, Median is the middle observation. Therefore 40 is the median.
(ii) Yes, there are two modes 38 and 43.
Question 4.
Find the mode and median of the following data :
13, 16, 12, 14, 19, 12, 14, 13, 14.
Solution:
We arrange the data in ascending order, we get,
12, 12, 13, 13, 14, 14, 14, 16,19.
Therefore, mode of this data is 14 because it occurs three times more than other observations.
Now, median is the middle observation. Therefore 14 is the median.
Question 5.
Tell whether the statement is true or false:
(i) The mode is always one of the numbers in a data.
(ii) The mean can be one of the numbers in a data.
(iii) The median is always one of the numbers in a data.
(iv) A data always has a mode.
(v) The data 6, 4, 3, 8, 9,12,13, 9 has mean 9.
Solution:
(i) False, (ii) Yes, (iii) Yes, (it;) Yes,
(v) Mean = \(\frac{6+4+3+8+9+12+13+9}{8}=\frac{64}{8}\) = 8
∴ False.