A New Modified Trimmed Mean for Estimating Confidence Interval of Mean for Skewed Populations

• Activity Number: 78
• Type: Contributed
• Date/Time: Sunday, August 3, 2014 : 4:00 PM to 5:50 PM
• Sponsor: Section on Statistical Computing
• Author(s): Tanweer Shapla*+ and Khairul Islam
• Companies: Eastern Michigan University and Eastern Michigan University
• Keywords: Student's t ; Mad t ; Median t ; Modified trimmed mean ; Confidence interval ; Coverage probability

Abstract

In this paper, we propose a new modified trimmed mean for the point and confidence interval (CI) estimate of the mean of skewed populations. The performances of the proposed estimates have been compared using real life examples and a simulation study with the Student's t, mad t, median t and trimmed t for varying levels of skewness in the populations. From the results of examples and simulation study, it appears that with skewed distribution, the proposed trimmed t and modified trimmed t CIs are as good as mad t or median t CIs in coverage probability consideration. With lower percent trimmed, trimmed and modified trimmed t CIs are identical or close to the Student's t CI, and with increased percentage trimmed, they are identical or close to the median t CI.