NCERT Solutions Class 11, Economics, Statistics for Economics, Chapter- 4, Presentation of Data
1. Bar diagram is a:
(a) one-dimensional diagram
(b) two-dimensional diagram
(c) diagram with no dimension
(d) none of these
Solution:
(a) one-dimensional diagram
Bar diagram is a one-dimensional diagram as these are presented on a plane having two axis in form of rectangular bars. The width is of no concern and only the length shows the frequency of the class interval.
2. Data represented through a histogram can help in finding graphically the:
(a) mean
(b) mode
(c) median
(d) all of these
Solution:
(b) mode
Histogram gives the value of mode of the frequency distribution presented graphically with the help of the tallest rectangle.
3. Ogives can be helpful in locating graphically the:
(a) mode
(b) mean
(c) median
(d) none of these
Solution:
(c) median
Intersection point of the more than and less than ogives gives the value of the median.
4. Data represented through arithmetic line graph help in understanding:
(a) long term trend
(b) cyclicity in data
(c) seasonality in data
(d) all of the above
Solution:
(a) long term trend
Arithmetic line graph assists in knowing the periodicity, trend, etc. in a long term time series data.
5. Width of bars in a bar diagram need not be equal. (True/False)
Solution:
False
Bar diagram consist of a group of equiwidth and equispaced rectangular bars for each set of data.
6. Width of rectangles in a histogram should essentially be equal. (True/False)
Solution:
False
When the class intervals are of same width, then the rectangular area are proportional to their corresponding frequencies and width of rectangles are equal. But, sometimes it is useful or required to use different width of class intervals and hence width of rectangles are unequal.
7. Histogram can only be formed with continuous classification of data. (True/False)
Solution:
True
A histogram is useful for showing only continous data and not for discrete series or data. If the classes are not continuous in nature, then one have to first convert it into continuous intervals.
8. Histogram and column diagram are the same method of presentation of data. (True/False)
Solution:
False
Histogram is a two-dimensional diagram which is useful for showing continuous data and the rectangles do not have the spaces between them, whereas column diagram is one-dimensional diagram having spaces between every bar or rectangle.
9. Mode of a frequency distribution can be known graphically with the help of histogram. (True/False)
Solution:
True
Histogram gives the value of mode of the frequency distribution presented graphically and gives the value through the tallest rectangle.
10. Median of a frequency distribution cannot be known from the ogives. (True/False)
Solution:
False
Intersection point of the more than and less than ogives gives the value of median.
11. What kind of diagrams are more effective in representing the following?
(a) Monthly rainfall in a year
(b) Composition of the population of Delhi by religion
(c) Components of cost in a factory
Solution:
(a) The monthly rainfall in a year can be easily represented by using a bar diagram because of only one variable, i.e., monthly rainfall. The months are plotted on x-axis and rainfall on Y-axis.
(b) Composition of the population of Delhi by religion is best represented by using a component bar diagram. It displays the bar and its sub-divisions into two or more components. Therefore, the total population can be sub divided on the basis of religion and presented using a component bar diagram.
(c) Components of the cost in a factory can easily be represented using a pie chart. The circle signifies the total cost and several components of the costs are presented by different portions of the circle drawn as per the percentage of total cost.
12. Suppose you want to emphasise the increase in the share of urban non-workers and lower level of urbanisation in India as shown in Example 4.2. How would you do it in the tabular form?
Solution:
Share of urban workers and non-workers in India
|
Location |
|
Sex |
Worker in urban (in crore) |
Non-worker in urban (in crore) |
Total |
Male |
50 |
70 |
120 |
Female |
25 |
50 |
75 |
Total |
75 |
120 |
195 |