startistik

Percentile

Posted on Monday, April 16, 2012

Percentile are values ​​that divide a cluster observations into one hundred equal parts. These values, denoted by P1, P2, ... P99, have the property that 1% of the data falls below P1, 2% of the data falls below P2 ..., and 99% of the data fall below P99.

Meanwhile, to calculate percentile of the data that has been arranged in the form of frequency distributions (grouped data), use the following formula.
 
 

 50th percentile, decile to-5 and the second quartile of a distribution is called the median. Quartiles and deciles also a percentile. For example, to the 7th decile is the 70th percentile, and the second quartile is also the 50th percentile.

 Desile

Posted on Wednesday, February 1, 2012

Desile are values ​​that divide a cluster observations into ten equal parts. These values, denoted by D1, D2, ..... D9, has properties that fall below 10% of the data D1, 20% of the data fall below D2, ..., and 90% of the data fall below the D9.

Example: Calculate Desile that to-7 D7 to data contained in the following table
 
Answer: How to calculate exactly the way desile determine quartile. To determine the age distribution of D7 for battery, have found the values ​​to which there is (70/100) X 40 = 28 pengamtan. Therefore, this value can be any value between 3.7 berup years and 3.8 years hence, is taken so that the average D7 = 3.75 years.

So it can be concluded that 70% of all batteries of this type days will be less than 3.75 years.

As for the count desile of data that has been arranged in the form of frequency distributions (grouped data) used the following formula.