Statistics

Prepared by Golam Robbani Ahmed(TGT Math)KV HPCL Jagiroad

CHAPTER: StatisticsCHAPTER: StatisticsFor class IXFor class IX

StatisticsStatistics is the science of collection,presentation,analysis and interpretation of data. Data are mainly two types:1.Primary Data(Self collected data)2.Seconadary data(collected from published or unpublished soueces)

The statistical mean is commonly called the average:

To find the mean of a group of numbers:Add the numbers togetherDivide by how many numbers were added together.

Measures of central tendency is the average or central value. AM,GM,Median, Mode etc.

The statistical median is middle number of a group of numbers that have been arranged in order by size.

On the other hand if the number of term is even than the

ModeA statistical mode is the value(s) that occur most frequently in the data set.Example: Find mode for the data3, 7, 5, 13, 20, 23, 39, 23, 40, 23, 14, 12, 56, 23, 29 Let us arrange the numbers in ascending orders: 3, 5, 7, 12, 13, 14, 20, 23, 23, 23, 23, 29, 39, 40, 56

This makes it easy to see which numbers appear most often.

In this case the mode is 23.More Than One ModeExample: {1, 3, 3, 3, 4, 4, 6, 6, 6, 9}

3 appears three times, as does 6.

So there are two modes: at 3 and 6

Mode: class interval with highest frequency is the mode class.