Statistics

Exercise 14.3 Part 2

Question 4: The length of 40 leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table:

Length (in mm)Number of Leaves
118 – 1263
127 – 1355
136 – 1449
145 – 15312
154 – 1625
163 – 1714
172 – 1802



(i) Draw a histogram to represent the given data.

Answer:

statistics histogram answer 4 figure

(ii) Is there any other suitable graphical representation for the same data?

Answer: Frequency Polygon

(iii) Is it correct to conclude that the maximum number of leaves are 153 mm long? Why?

Answer: No, because the data in a particular row shows a range rather than a single number.


Question 5: The following table gives the life times of 400 neon lamps:

Life Time (in hours)Number of Lamps
300 – 40014
400 – 50056
500 – 60060
600 – 70086
700 – 80074
800 – 90062
900 – 100048

(i) Represent the given information with the help of a histogram.

Answer:

statistics histogram answer 5 figure

(ii) How many lamps have a life time of more than 700 hours?

Answer: 184

Question 6: The following table gives the distribution of students of two sections according to the marks obtained by them:

Section ASection B
MarksFrequencyMarksFrequency
0 – 1030 – 105
10 – 20910 – 2019
20 – 301720 – 3015
30 – 401230 – 4010
40 – 50940 – 501

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.

Answer:

statistics frequency polygon answer 5 figure

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