7th Class Mathematics Data Handling Histogram

     Histogram

It.is a graphical representation of frequency distribution in which class-intervals are taken along x - axis and frequency are taken along y - axis.  

      Frequency Polygon

The curve obtained by joining midpoints of successive tops of the rectangles of a histogram represents frequency polygon.        

• Data is defined as the particular information in numeric form.
• Mean \[=\frac{sum\,of\,observation}{Total\,number\,of\,observation}\] 
• If the number of observations is odd then median \[={{\left( \frac{n+1}{2} \right)}^{th}}\] observation
• If the number of observations is even Median \[=\frac{{{\left( \frac{n}{2} \right)}^{th}}observation+{{\left( \frac{n}{2}+1 \right)}^{th}}observation}{2}\]
• Mode is defined as the value of variable which has highest frequency.      

• Stat-etymology was the early applications of statistical thinking revolved around the needs of states to base policy on demographic and economic data.
• Statistics help in prediction and forecasting using data and statistical models
• There are four main levels of measurement used in statistics: ratio, interval, nominal and ordinal.