Q19 of 26 Page 14

The time taken, in seconds, to solve a problem by each of 25 pupils is as follows:

16, 20, 26, 27, 28, 30, 33, 37, 38, 40, 42, 43, 46, 46, 46, 48, 49, 50, 53, 58, 59, 60, 64, 52, 20


(a) Construct a frequency distribution for these data, using a class interval of 10 seconds.


(b) Draw a histogram to represent the frequency distribution.

To Find:

(a) Frequency distribution for the given data


(b) Histogram for the data


Given:


Data of time taken by 25 students [to solve a problem


Concept Used:


Histogram: a diagram consisting of rectangles whose area is proportional to the frequency of a variable and whose width is equal to the class interval.


The frequency of observation is the number of times that observation occurs.


Explanation:


Frequency distribution for the data is as follows:



Now, on the basis of frequency distribution, we can find out the histogram as follows:



More from this chapter

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17

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


(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?

 18

The runs scored by two teams A and B on the first 60 balls in a cricket match are given below:


Represent the data of both the teams on the same graph by frequency polygons.


[Hint: First make the class intervals continuous.]

 20

Find the mean of the following data:

 21

Find the value of p for the following distribution whose mean is 16.6.