How would one go about calculating the mean excluding the top 25% and bottom 25% (the 1st and 3rd quartiles) Take the following range for instance…? 0.62% 0.34% 1.20% 0.68% 0.78% 1.00% 0.92% 1.01% 1.30% 0.85% 0.84% 0.74%

3rd is not the top; that’d be the 4th. You have 12 observations. Eliminate the top 3 and the bottom 3. Find the middle of the six remaining.

Hi First arrange the data in ascending order 0.34% 0.62% 0.68% 0.74% 0.78% 0.84% 0.85% 0.92% 1.00% 1.01% 1.20% 1.30% Then find out top 25th Quartile, i.e. 12*(25/100) = 3rd Element from Bottom in above ditribution (1.01%) This represents that 75% of the data is below Similarly find out Bottom 25th Quartile = 3rd Element from Top in above distribution (0.68%) Now find Mean of the data excluding Values Below / Above the Quartiles mentioned above The answer sould be 0.86%