Length (in mm) | Number of leaves |
---|---|
118 − 126 | 3 |
127 − 135 | 5 |
136 − 144 | 9 |
145 − 153 | 12 |
154 − 162 | 5 |
163 − 171 | 4 |
172 − 180 | 2 |
(i) Draw a histogram to represent the given data.
(ii) Is there any other suitable graphical representation for the same data?
(iii) Is it correct to conclude that the maximum number of leaves are 153 mm long? Why?
(i) Let us find half the difference between lower limit of a class and upper limit of its preceding class to make the continuous distribution.
Length (in mm) | Number of leaves |
---|---|
117.5 − 126.5 | 3 |
126.5 − 135.5 | 5 |
135.5 − 144.5 | 9 |
144.5 − 153.5 | 12 |
153.5 − 162.5 | 5 |
162.5 − 171.5 | 4 |
171.5 − 180.5 | 2 |
Representation of given data in the form of a histogram is as follows:
Length of 40 leaves of a plant measured correct to one millimeter. Scale chosen: On y-axis – 1 large division, i.e. 1 cm = 1 leave
(ii) Yes, we can represent the given data by other graphical representation named as Frequency Polygon which is as follows:
Length in mm | Class mark | Number of leaves |
---|---|---|
117.5-126.5 | 122 | 3 |
126.5-135.5 | 131 | 5 |
135.5-144.5 | 140 | 9 |
144.5-153.5 | 149 | 12 |
153.5-162.5 | 158 | 5 |
162.5-171.5 | 167 | 4 |
171.5-180.5 | 176 | 2 |
(iii) No, because the maximum number 12 is corresponding to the class interval 145 -153 which implies that the leaves whose length are 145 mm or less than 153 mm are maximum in number.
Section A | Section B | ||
---|---|---|---|
Marks | Frequency | Marks | Frequency |
0 − 10 | 3 | 0 − 10 | 5 |
10 − 20 | 9 | 10 − 20 | 19 |
20 − 30 | 17 | 20 − 30 | 15 |
30 − 40 | 12 | 30 − 40 | 10 |
40 − 50 | 9 | 40 − 50 | 1 |
Represent the marks of the students of both the sections on the same graph by two frequency polygons. From the two polygons compare the performance of the two sections.
Section | Number of girls per thousand boys |
---|---|
Scheduled Caste (SC) | 940 |
Scheduled Tribe (ST) | 970 |
Non-SC/ST | 920 |
Backward districts | 950 |
Non-backward districts | 920 |
Rural | 930 |
Urban | 910 |
(i) Represent the information above by a bar graph.
(ii) In the classroom discuss what conclusions can be arrived at from the graph.
Length (in hours) | Number of lamps |
---|---|
300 − 400 | 14 |
400 − 500 | 56 |
500 − 600 | 60 |
600 − 700 | 86 |
700 − 800 | 74 |
800 − 900 | 62 |
900 − 1000 | 48 |
(i) Represent the given information with the help of a histogram.
(ii) How many lamps have a lifetime of more than 700 hours?
Number of letters | Number of surnames |
---|---|
1 − 4 | 6 |
4 − 6 | 30 |
6 − 8 | 44 |
8 − 12 | 16 |
12 − 20 | 4 |
(i) Draw a histogram to depict the given information.
(ii) Write the class interval in which the maximum number of surnames lie.
Age (in years) | Number of children |
---|---|
1 − 2 | 5 |
2 − 3 | 3 |
3 − 5 | 6 |
5 − 7 | 12 |
7 − 10 | 9 |
10 − 15 | 10 |
15 − 17 | 4 |
Draw a histogram to represent the data above.
In Fig. 9.26, A, B, C and D are four points on a circle. AC and BD intersect at a point E such that ∠ BEC = 130° and ∠ ECD = 20°. Find ∠ BAC.
Statistics is a field of mathematics concerned with the study of data collection, data analysis, data interpretation, data presentation, and data organization. Statistics is mainly used to acquire a better understanding of data and to focus on specific applications. Also, Statistics is the process of gathering, assessing, and summarising data in a mathematical form.
Using measures of central tendency and measures of dispersion, the descriptive technique of statistics is utilized to describe the data collected and summarise the data and its attributes.
This statistical strategy is utilized to produce conclusions from data. Inferential statistics rely on statistical tests on samples to make inferences, and it does so by discovering variations between the two groups. The p-value is calculated and differentiated to the probability of chance() = 0.05. If the p-value is less than or equivalent to, the p-value is considered statistically significant.