Testing for equality of means with equal and unequal variances

2021 ◽  
Vol 20 (2) ◽  
pp. 51-60
Author(s):  
A.O. Abidoye ◽  
W.A. Lamidi ◽  
M.O. Alabi ◽  
J. Popoola
Keyword(s):  
Agricultural Development ◽  
Secondary Data ◽  
Development Project ◽  
T Test ◽  
Harmonic Mean ◽  
Test Statistics ◽  
Test Statistic ◽  
Unequal Variances ◽  
Equality Of Means ◽  
Pooled Sample

In this paper, we are interested in comparing the conventional t –test with the proposed t – test for testing equality of means with unequal and equal variances. Here, we proposed harmonic mean of variances as an alternative to the pooled sample variance when there is heterogeneity of variances. Two sets of secondary data were obtained from Agricultural Development Project (KWADP) and the Ministry of Agriculture in Ilorin, Kwara State to demonstrate the two test statistics used and the results show that the proposed t – test statistic is found to be appropriate than the conventional t – test statistic when we have unequal variances but the conventional t – test perform better when we have equal variances.

scholarly journals A NOTE ON THE CONVENTIONAL OUTLIER DETECTION TEST PROCEDURES

2015 ◽  
Vol 21 (2) ◽  
pp. 433-440 ◽  
Author(s):  
JIANFENG GUO
Keyword(s):  
Outlier Detection ◽  
Goodness Of Fit ◽  
T Test ◽  
Test Statistics ◽  
Test Statistic ◽  
Test Procedures ◽  
Global Test ◽  
Normal Test ◽  
Student’S T ◽  
Student’S T Test

Under the assumption of that the variance-covariance matrix is fully populated, Baarda's w-test is turn out to be completely different from the standardized least-squares residual. Unfortunately, this is not generally recognized. In the limiting case of only one degree of freedom, all the three types of test statistics, including Gaussian normal test, Student's t-test and Pope's Tau-test, will be invalid for identification of outliers: (1) all the squares of the Gaussian normal test statistic coincide with the goodness-of-fit (global) test statistic, even for correlated observations. Hence, the failure of the global test implies that all the observations will be flagged as outliers, and thus the Gaussian normal test is inconclusive for localization of outliers; (2) the absolute values of the Tau-test statistic are all exactly equal to one, no matter whether the observations are contaminated. Therefore, the Tau-test cannot work for outlier detection in this situation; and (3) Student's t-test statistics are undefined.

scholarly journals Rounded Input Variables, Exact Test Statistics (RIVETS)

2019 ◽  
Author(s):  
Nicholas J. L. Brown ◽  
James Heathers
Keyword(s):  
Statistical Tests ◽  
T Test ◽  
Test Statistics ◽  
Test Statistic ◽  
Statistical Software ◽  
Exact Test ◽  
Manual Intervention ◽  
Software Packages ◽  
Rounded Form ◽  
Input Variables

Most statistical software packages report the input values to statistical tests (e.g., means and standard deviations for an unpaired t test) in a rounded form (e.g., to two decimal places), with this rounding having been performed after the test statistic has been calculated. However, in some cases, the input values are rounded before the test statistic is calculated, most likely because of some form of manual intervention by the researcher. We describe a method that enables the probabilistic identification of detecting this rounding, the conditions required for this method to be applicable, the tests where pre-calculation rounding can be detected, and the implications of its detection.

PENGARUH KOMPETENSI, MOTIVASI, DAN KOMUNIKASI TERHADAP KINERJA PEGAWAI PADA DINAS PEKERJAAN UMUM DAN PENATAAN RUANG KABUPATEN BANDUNG BARAT

2019 ◽  
Vol 2 (2) ◽  
pp. 1-14
Author(s):  
Lydia Novi Yanti
Keyword(s):  
Case Studies ◽  
Secondary Data ◽  
T Test ◽  
Civil Servants ◽  
Quantitative Approach ◽  
Research Approach ◽  
Validity And Reliability ◽  
F Test ◽  
Simultaneous Test

This research is conducted in order to assess the effect of competency, motivation, and communication on employee’s performance (case studies at Dinas Pekerjaan Umum dan Penataan Ruang West Bandung Regency) partially and simultaneously. There are many factors that affect the employee’s performance, but this research is only limited to the factors of competency, motivation, and communication. The researcher used primary and secondary data. The research approach used is quantitative approach which the samples are 55 civil servants which is assessed by 5 Heads of Fields and 2 Heads Sub-Division. Before analyzing, all research validity and reliability instruments are examined. After the data are valid and reliable then analyzed by using classical assumption test, partial test (t test), and simultaneous test (F test) helping by IBM SPSS version 23 software. The result of analysis showed that competency, motivation, and communication variables are affected positively significantly and partially to the employee’s performance. Competency, motivation, and communication variables simultaneously affected positively and significantly about 54,3% and the rest is about 45,7% affected by other variable that is not observed in this research.  

scholarly journals Effects of kinship correction on inflation of genetic interaction statistics in commonly used mouse populations

2021 ◽  
Author(s):  
Anna L Tyler ◽  
Baha El Kassaby ◽  
Georgi Kolishovski ◽  
Jake Emerson ◽  
Ann E Wells ◽  
...  
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Genetic Interaction ◽  
Recombinant Inbred Lines ◽  
Test Statistics ◽  
Test Statistic ◽  
Kinship Matrix ◽  
Main Effect ◽  
Main Effects ◽  
Interaction Test

Abstract It is well understood that variation in relatedness among individuals, or kinship, can lead to false genetic associations. Multiple methods have been developed to adjust for kinship while maintaining power to detect true associations. However, relatively unstudied, are the effects of kinship on genetic interaction test statistics. Here we performed a survey of kinship effects on studies of six commonly used mouse populations. We measured inflation of main effect test statistics, genetic interaction test statistics, and interaction test statistics reparametrized by the Combined Analysis of Pleiotropy and Epistasis (CAPE). We also performed linear mixed model (LMM) kinship corrections using two types of kinship matrix: an overall kinship matrix calculated from the full set of genotyped markers, and a reduced kinship matrix, which left out markers on the chromosome(s) being tested. We found that test statistic inflation varied across populations and was driven largely by linkage disequilibrium. In contrast, there was no observable inflation in the genetic interaction test statistics. CAPE statistics were inflated at a level in between that of the main effects and the interaction effects. The overall kinship matrix overcorrected the inflation of main effect statistics relative to the reduced kinship matrix. The two types of kinship matrices had similar effects on the interaction statistics and CAPE statistics, although the overall kinship matrix trended toward a more severe correction. In conclusion, we recommend using a LMM kinship correction for both main effects and genetic interactions and further recommend that the kinship matrix be calculated from a reduced set of markers in which the chromosomes being tested are omitted from the calculation. This is particularly important in populations with substantial population structure, such as recombinant inbred lines in which genomic replicates are used.

scholarly journals Actors’ Satisfaction with Poultry Value Chain Approach of the Commercial Agricultural Development Project in Enugu State, Nigeria

2019 ◽  
Vol 23 (4) ◽  
pp. 157
Author(s):  
Charles Ekene Udoye ◽  
Mabel Ukamaka Dimelu ◽  
Ifeoma Q. Anugwa ◽  
Remigius I. Ozioko ◽  
Favour C. Azubuike
Keyword(s):  
Value Chain ◽  
Agricultural Development ◽  
Development Project ◽  
Enugu State

A test for fuzzy exponentiality based on Kullback-Leibler information

2021 ◽  
pp. 1-8
Author(s):  
Lingtao Kong
Keyword(s):  
Biological Sciences ◽  
Monte Carlo ◽  
Goodness Of Fit ◽  
Experimental Studies ◽  
Real Data ◽  
Test Statistics ◽  
Test Statistic ◽  
Goodness Of Fit Test ◽  
Higher Power ◽  
Leibler Information

The exponential distribution has been widely used in engineering, social and biological sciences. In this paper, we propose a new goodness-of-fit test for fuzzy exponentiality using α-pessimistic value. The test statistics is established based on Kullback-Leibler information. By using Monte Carlo method, we obtain the empirical critical points of the test statistic at four different significant levels. To evaluate the performance of the proposed test, we compare it with four commonly used tests through some simulations. Experimental studies show that the proposed test has higher power than other tests in most cases. In particular, for the uniform and linear failure rate alternatives, our method has the best performance. A real data example is investigated to show the application of our test.

scholarly journals Infrastruktur Jalan Terhadap Peningkatan Kinerja Ukm Tas

INOVATOR ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 168
Author(s):  
Leny Muniroh
Keyword(s):  
Production Function ◽  
Data Use ◽  
Secondary Data ◽  
T Test ◽  
Positive Sign ◽  
Infrastructure Development ◽  
Independent Variables ◽  
Medium Enterprise ◽  
Positive Effect ◽  
Observation Period

<p>The research objective are to analyze handbag Small-Medium Enterprise (SME) performance and the effect of infrastructure development on MSE performances in Bojong Rangkas Village, District of Ciampea, Bogor Regency. The research conducted from Pebruary to May 2010. Primary and secondary data use to the purposes. The sampling consisted of 30 SME respondents for observation period 2008 and 2009. The production function specified using Cobb-Douglass. The regression results indicated the model significant at ? = 0.05. Sig-t test indicates that all independent variables shows positive sign. At ? = 0.30, labor (0.172), material (0.000) and dummy year (0.272) has positive and significant effect on production. This result indicate that road infrastructre development has positive effect on handbag SME production. As reccomendation, there is a need another support such as soft infrastructure (training) to realize the location as center of handbag SME in the regency</p>

scholarly journals ANALISIS SEKTOR BASIS DAN SUBSEKTOR PERTANIAN BASIS TERHADAP PERTUMBUHAN EKONOMI DI KABUPATEN KEEROM, PROVINSI PAPUA

2017 ◽  
Vol 13 (1) ◽  
pp. 10
Author(s):  
Usman Usman
Keyword(s):  
Economic Growth ◽  
Agricultural Development ◽  
Development Program ◽  
Secondary Data ◽  
Animal Husbandry ◽  
Position Change ◽  
Location Quotient ◽  
Location Factor ◽  
Agriculture Sector ◽  
Dynamic Location

Agricultural  development  program  in  Indonesia  is  the  part  of  economic development.  Papua  Province  in  the  economic  sector,  the  agriculture  sector  is  the very important role in supporting economic growth in the region.This study aims to analyze  the  basic  sector  and  basic  sub-sector  of  agriculture,  analyze  the  position sector  and  the  agriculture  sector  in  the  future,  and  the  determinants  of  changes  in positions on regional economic growth based on the calculation of the GDP Keerom district  and  Papua  province  in  2008-2011.The  study  used  secondary  data  over  a period of four years. The analysis  method used is Location Quotient (LQ), Dynamic Location  Quotient  (DLQ),  and  Total  Shift  Share  (TSS).  The  analysis  LQ  show  that agriculture  sector  is  the  basic  sector  in  the  economy  Keerom.While  the  agriculture sector  as  the  sub-sector  basis  (leading  sector) is plantation,  animal  husbandry,  and forestry.The combined method of LQ and DLQ, show that agriculture sector is still the sector basis in the future.The results of the analysis TSS is known that the deciding factor  position  change  on  plantations  and  fishing  sub-sector  is  the  location  factor, while the determining factor position change on the livestock sector is the factor of of economic structure.

scholarly journals Pengaruh Pembiayaan Mudharabah Dan Pembiayaan Musyarakah Terhadap Return Of Asset (Roa) Pada Bank Syariah Mandiri

2019 ◽  
Vol 4 (2) ◽  
pp. 277
Author(s):  
Ratih Komala Dewi
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Quantitative Method ◽  
Secondary Data ◽  
Financial Statements ◽  
Positive Influence ◽  
Test Statistics ◽  
Interesting Conclusion ◽  
The Subject ◽  
Spss Software

 The study aims to determine the effect of Mudharabah Financing and Musyarakah Financing on Return of Assets (RoA) in Bank Mandiri Syariah in 2014-2018. The method of data collection in the subject of research was obtained by tabulating secondary data in the form of financial statements at Bank Mandiri Syariah in 2014 - 2018. The quantitative method of data analysis was done by processing SPSS software data in the form of classic assumption testing, testing F test statistics and testing t test to draw interesting conclusion. The results of this study indicate Mudharabah Financing and Musyarakah Financing have a positive influence on Return of Assets (RoA) in Bank Mandiri Syariah in 2014-2018 both partially and simultaneously.

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