Which graph is used to represent data in continuous elements?

Consider the following statements in terms of histogram:

I. The histogram is a suitable representation of a frequency distribution of a continuous variable.

II. The area included under the whole histogram is the total frequency.

Which of the above statement(s) is / are correct?

Consider the following statements in terms of histogram.

I. The total area of the rectangles in a histogram is equal to the total area bounded by the corresponding frequency polygon and the $X$ - axis.

II. When class intervals are unequal in a frequency distribution, then area of the rectangle is proportional to the frequency.

Which of the above statement(s) is/are correct?

The curve given below represents a/an

A set of annual numerical data, comparable over the years, is given for the last $12 \mathrm{yr}$. Consider the following statements

$\mathrm{I}$. The data is best represented by a broken line graph, each corner (turning point) representing the data of one year.

$\mathrm{II}$. Such a graph depicts the chronological change and also enables one to make a short term forecast.

Which of the above statement(s) is/are correct?

Consider the following statements

The appropriate number of classes while constructing a frequency distribution should be chosen such that

$\mathrm{I}.$ The class frequency first increases to a peak and then declines.

$\mathrm{II}.$ The class frequency should cluster around the class midpoint.

Which of the above statement(s) is$/$are correct$?$

Consider the following statements:

$\mathrm{I}$. A continuous random variable can take all values in an interval.

$\mathrm{II}$. A random variable which takes a finite number of values is necessarily discrete.

$\mathrm{III}$. Construction of a frequency distribution is based on data which are discrete.

Which of the above statement(s) is/are correct?