The data which changes over a period of time can be displayed through a line graph. In line graph:● Points are plotted on the graph related to two variables ● Points are joined by the line segments. How to Construct a Line Graph? Steps of construction of line graph: On a graph, draw two lines perpendicular to each other intersecting at O. The horizontal line is x-axis … [Read more...]

## Construction of Pie Chart

Now we will discuss about the construction of pie chart or pie graph. In brief let us recall about, what is a pie chart? It is a circular graph which is used to represent data. In this : ● Various observations of the data are represented by the sectors of the circle. ● The total angle formed at the centre is 360°. ● The whole circle represents the sum of the values of all … [Read more...]

## Median

Median of a group of observation is the value which lies in the middle of the data (when arranged in an ascending or descending order) with half of the observations above it and the other half below it. ● When the number of observations (n) is odd. Then, median is (n + 1)/2 th observation. ● When the number of observations (n) is even. Then median is the mean of … [Read more...]

## Mode

For a set of given observation, mode is that observation which occurs maximum number of times.1. Find the mode of the given set of number2, 2, 3, 5, 4, 3, 2, 3, 3, 5Solution:Arranging the number with same values together, we get2, 2, 2, 3, 3, 3, 3, 4, 5, 5We observe that 3 occurs maximum number of times, i.e., four.Therefore, mode of this data is 3.Note:A data may not have a … [Read more...]

## Mean of the Tabulated Data

In the mean of the tabulated data, if the frequencies of n observations x1, x2, x3, ………. xn are f1, f2, f3 ………. fn, then Mean of the tabulated data= (f1x1 + f2x2 + f3x3 ……… fnxn)/( f1 + f2 + f3 ………. fn) = (∑ fixi)/(∑fi)Worked-out examples on mean of the tabulated data:1. Find the mean weight of 50 girls from the following table.Weight in kg 40 42 34 36 46 No. of girls … [Read more...]

## Mean

Mean or average or arithmetic mean is one of the representative values of data. We can find the mean of observations by dividing the sum of all the observations by the total number of observations. Mean of raw data: If x1, x2, x3, ……. xn are n observations, thenArithmetic Mean = (x1, x2, x3, ……. xn)/n= (∑xi)/n∑ (Sigma) is a Greek letter showing summation 1. Weights of 6 boys … [Read more...]

## Construction of Bar Graphs

Now we will discuss about the construction of bar graphs or column graph. In brief let us recall about, what is bar graph?Bar graph is the simplest way to represent a data. ● In consists of rectangular bars of equal width.● The space between the two consecutive bars must be the same. ● Bars can be marked both vertically and horizontally but normally we use … [Read more...]

## Class Limits in Exclusive and Inclusive Form

In class boundaries and class limits in exclusive and inclusive form we will mainly discuss about; ● Class limits and class boundaries in exclusive and inclusive forms ● Class interval, class mark, range of the dataClass limits in exclusive and inclusive form: ● In exclusive form, the lower and upper limits are known as true lower limit and true upper limit of the … [Read more...]

## Use of Tally Marks

Here we will learn how to use of tally marks.When the observations are large, it may not be easy to find the frequencies by simply counting, so we make the use of bass (|, \) called the tally marks. Tallies are usually marked in bunches of five. The first four tallies are marked vertically. The fifth tally in a bunch is marked diagonally across the earlier 4. … [Read more...]

## Frequency Distribution of Ungrouped and Grouped Data

Frequency distribution of ungrouped and grouped data is discussed below with examples. Frequency distribution of ungrouped data:Given below are marks obtained by 20 students in Math out of 25.21, 23, 19, 17, 12, 15, 15, 17, 17, 19, 23, 23, 21, 23, 25, 25, 21, 19, 19, 19 Frequency distribution of grouped data: The presentation of the above data can be expressed into groups. … [Read more...]