### Theory:

We know that histograms are created on continuous data.

Let us consider the data table given below and try to construct a histogram step-by-step.

Problem:

A private organization conducted a survey across hundred schools in Chennai. The organization collected the average number of kindergarten children in each classroom.

The data table looks like this:

 Number of students $$25$$ - $$30$$ $$30$$ - $$35$$ $$35$$ - $$40$$ $$40$$ - $$45$$ $$45$$ - $$50$$ Frequency $$15$$ $$35$$ $$18$$ $$25$$ $$7$$

Now, let us try to construct a histogram.

Step $$1$$: Convert the data received into continuous data.

Here, the data is already in continuous form. Hence, no conversion is required.

Step $$2$$: Select appropriate names and units for $$X$$-axis and $$Y$$-axis.

Here, the axes will look like this:

Step $$3$$: Now mark the class intervals along the $$X$$-axis, and the frequency along the $$Y$$-axis.

Step $$4$$: Now, construct rectangles with class intervals as the base, and the frequency as the height.