APPLICATION OF A T - STATISTIC FOR TESTING EQUALITY OF MEANS WITH DIRECTIONAL ALTERNATIVE WHEN POPULATION VARIANCES ARE UNEQUAL
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Date
2018
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FUW Trends in Science & Technology Journal
Abstract
In this study, we proposed a test statistic for testing equality of means when variances are not equal. When
variances of different groups are significantly different from one another it is not proper to use the pooled sample
variance (SP2) as a single value for the variances. In this work we are interested in testing directional hypothesis,
since the variances are unequal then we make use of harmonic mean variance (SH2). The means are ranked such
that the problem reduces to a two sample situations. Data set from Kwara State Ministry of Agriculture on the yield
of maize (kilograms) in four different locations was used to demonstrate directional hypothesis testing.
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Keywords
Harmonic mean of variances, chi-square distribution, directional alternative hypothesis