Question

If there are too many data points, say in the order of thousands, is it feasible to plot bar graphs manually?
If not, then plotting of which type of graph is favorable?

Answer 1

Bar graphs are not feasible to plot when a data set has large number of data points.

In such cases, we group the data in equal intervals and generate a grouped frequency table, using which we can plot histogram.

Consider the data of number of students in a community with respect to their ages: Age (Years) Number of Students Age (Years) Number of Students

6	5	15	30
7	15	19	16
9	25	20	15
10	35	25	15
12	24	29	10

Rather than plotting each data, we group them in to equal intervals as shown: Age Groups Number of Students

$0\le \text{Age}<10$	$5+15+25=45$
$10\le \text{Age}<20$	$35+24+30+16=105$
$20\le \text{Age}<30$	$15+15+10=40$

The corresponding histogram is as follows: