Question

Question 4 (i)
The length of 40 leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table:
$$\begin{array}{cc}Length\left(inmm\right)& Numberofleaves\\ 118-126& 3\\ 127-135& 5\\ 136-144& 9\\ 145-153& 12\\ 154-162& 5\\ 163-171& 4\\ 172-180& 2\end{array}$$
(i) Draw a histogram to represent the given data.

Answer 1

(i) It can be observed that the length of leaves is represented in a discontinuous class interval having a difference of 1 in between them. Therefore,$\frac{1}{2}=0.5$ has to be added to each upper class limit and also have to subtract 0.5 from the lower class limits so as to make the class intervals continuous.
$$\begin{array}{cc}Length\left(inmm\right)& Numberofleaves\\ 117.5-126.5& 3\\ 126.5-135.5& 5\\ 135.5-144.5& 9\\ 144.5-153.5& 12\\ 153.5-162.5& 5\\ 162.5-171.5& 4\\ 171.5-180.5& 2\end{array}$$

Taking the length of leaves on x-axis and the number of leaves on y-axis, the Histogram of this information can be drawn as above.
Here, 1 unit on y-axis represents 2 leaves.