Question

Draw frequency distribution table and bar graph for the following data :

Speed of typists, in words per minute:

$76,75,80,78,75,80,80,75,75,78,76,76,75,78,79,80,79,79,79,75,75,76,77,77,77,75,77,77,80,79,78,76$

$78,76,76,75,78,79,80,80,77,78,76,77,78,79,80,79,78,77$

Answer 1

Step $1:$ Drawing frequency distribution table

Given data, $76,75,80,78,75,80,80,75,75,78,76,76,75,78,79,80,79,79,79,75,75,76,77,77,77,75,77,77,80,79,78,76$

$78,76,76,75,78,79,80,80,77,78,76,77,78,79,80,79,78,77$

We will make frequency table by using tally marks.

Tally marks are the representation of the data in the form of vertical lines. We put one vertical line (|) for each of the four counts. A diagonal line (\) is put for the fifth count. These marks are tally marks.

Hence, distribution table for the given data given as-

Number	Tally Marks	Frequency
75		09
76		08
77		08
78		09
79		08
80		08
	Total	50

Step $2:$Drawing a bar graph:

Steps of constructing bar graph:

1. Mark the horizontal axis name as words per minute and the vertical axis as Number of typists.

2. Along the horizontal axis , choose bars of uniform (equal) width, with a uniform gap between them.

3. Choose a suitable scale to determine the heights of the bars, according to the space available for the graph. Here, we choose $1$ small division to represent $1$ Typists.

Hence, these are the frequency table and bar graph.