scholarly journals Two Studies in Automobile Insurance Ratemaking

1960 ◽  
Vol 1 (4) ◽  
pp. 192-217 ◽  
Author(s):  
Robert A. Bailey ◽  
LeRoy J. Simon
Keyword(s):  
The Other ◽  
Actual Data ◽  
Automobile Insurance ◽  
Chi Square ◽  
Canadian Experience ◽  
Multiple Classification ◽  
Chi Square Test ◽  
Best Fit ◽  
Improved Methods ◽  
Do So

Section A of this paper uses the Canadian experience for private passenger automobiles to show (1) that merit rating is almost as effective as the class plan in separating the better risks from the poorer risks, (2) that both merit rating and class rating leave unanalyzed a considerable amount of variation among risks and (3) that certain available evidence supports the conclusion that annual mileage, which has long been felt to be an important measure of hazard, is a very significant cause of this unanalyzed variation among risks.Section B presents a method for obtaining relativities among groups on which a multiple classification system has been imposed. The customary method of calculating class relativities uses the total experience for each class with all subdivisions within the classes added together. With the customary method it is difficult to make a completely accurate adjustment for different distributions by territory or merit rating, because any change in the class relativities disturbs the other sets of relativities and conversely. It is shown that even if such an adjustment were made, the customary method of calculating relativities one set at a time does not reflect the relative credibility of each subgroup and does not produce the best fit to the actual data. Moreover it produces differences between the actual data and the fitted values which are far too large to be caused by chance. In addition, for private passenger automobile insurance in Canada, it is shown that two sets of relativities which are multiplied together cannot produce the best fit to the actual data, and some of the consequences of trying to do so are explained. Some methods are advanced whereby all sets of relativities for classes, merit ratings, territories, and so forth, can be calculated simultaneously, which will overcome all the deficiencies in the customary method. These improved methods use the technique of minimizing a measure (technically known as the chi-square test) of the differences between the actual data and the fitted values. Some applications to other lines of insurance are mentioned.

Prediction of Haemoglobin Level by Some Probability Distribution

2020 ◽  
Vol 9 (1) ◽  
pp. 84-88
Author(s):  
Govinda Prasad Dhungana ◽  
Laxmi Prasad Sapkota
Keyword(s):  
Probability Distribution ◽  
Normal Distribution ◽  
Goodness Of Fit ◽  
Continuous Variable ◽  
Hemoglobin Level ◽  
Chi Square ◽  
Chi Square Test ◽  
Log Normal ◽  
Two Parameters ◽  
Best Fit

 Hemoglobin level is a continuous variable. So, it follows some theoretical probability distribution Normal, Log-normal, Gamma and Weibull distribution having two parameters. There is low variation in observed and expected frequency of Normal distribution in bar diagram. Similarly, calculated value of chi-square test (goodness of fit) is observed which is lower in Normal distribution. Furthermore, plot of PDFof Normal distribution covers larger area of histogram than all of other distribution. Hence Normal distribution is the best fit to predict the hemoglobin level in future.

scholarly journals Confronting Theories of Firm Growth in Light of Degrees-of-Freedom Analysis

2015 ◽  
Vol 22 (74) ◽  
pp. 385-404
Author(s):  
Sérgio Fernando Loureiro Rezende ◽  
Ricardo Salera ◽  
José Márcio de Castro
Keyword(s):  
Degrees Of Freedom ◽  
Firm Growth ◽  
Dynamic Capabilities ◽  
Statistical Tests ◽  
Explanatory Power ◽  
Stage Theory ◽  
Chi Square ◽  
Growth Optimum ◽  
Chi Square Test ◽  
Do So

This article aims to confront four theories of firm growth – Optimum Firm Size, Stage Theory of Growth, The Theory of the Growth of the Firm and Dynamic Capabilities – with empirical data derived from a backward-looking longitudinal qualitative case of the growth trajectory of a Brazilian capital goods firm. To do so, we employed Degree of Freedom-Analysis for data analysis. This technique aims to test the empirical strengths of competing theories using statistical tests, in particular Chi-square test. Our results suggest that none of the four theories fully explained the growth of the firm we chose as empirical case. Nevertheless, Dynamic Capabilities was regarded as providing a more satisfactory explanatory power.

scholarly journals Panoramic Radiographic Assessment of Agenesis of Mandibular Third Molars: A Hospital Based Study in Eastern Nepal

2019 ◽  
Vol 57 (217) ◽  
Author(s):  
Pragya Regmee ◽  
Jyotsna Rimal ◽  
Ichha Kumar Maharjan ◽  
Surya Raj Niraula
Keyword(s):  
Panoramic Radiograph ◽  
The Other ◽  
Third Molars ◽  
Radiographic Assessment ◽  
Review Committee ◽  
Oral Medicine ◽  
Chi Square ◽  
Institutional Review ◽  
Chi Square Test ◽  
Mandibular Third Molars

Introduction: Racial variation, genetic inheritance and various other factors can affect the jaw size and ultimately the tooth size and number. Studies for agenesis of mandibular third molars (M3s) have been carried out in various populations but data relating to these are not evident from most of the parts of Nepal. Hence, the objective of the present study is to determine the prevalence of agenesis among the population of patients visiting the Department of Oral Medicine and Radiology of this institute. The study also sought the odds of agenesis of M3 in one side when there was missing M3 on the other side of the mandible. Methods: This study was conducted after the approval from Institutional Review Committee of BPKIHS. Two hundred and eighty four patients (568 sites of M3, bilaterally), visiting the Department of Oral Medicine and Radiology were studied with Panoramic Radiograph to assess for agenesis of mandibular third molars, bilaterally. Percentage of agenesis was calculated and chi square test was applied where relevant. Odds ratio was also calculated. Results: Agenesis was seen in 28.7% of the participants. The Odds of M3 being missing on one side with concurrent missing M3 on the other side was 40.27 (Confidence Interval 19.34 to 83.87). Conclusions: Agenesis was highly prevalent in this study group. The likelihood of M3 being absent on one side, when there was concurrent missing M3 on the other side of mandible was also high.

scholarly journals Performance verification of anti-SARS-CoV-2-specific antibody detection by using four chemiluminescence immunoassay systems

2020 ◽  
Vol 57 (6) ◽  
pp. 429-434
Author(s):  
Yafang Wan ◽  
Zhijie Li ◽  
Kun Wang ◽  
Tian Li ◽  
Pu Liao
Keyword(s):  
False Positive ◽  
Detection System ◽  
False Positive Rate ◽  
Antibody Test ◽  
The Other ◽  
Antibody Detection ◽  
Igg Antibody ◽  
Chi Square ◽  
Chemiluminescence Immunoassay ◽  
Chi Square Test

Objectives The purpose of the current study was to evaluate the analytical performance of seven kits for detecting IgM/IgG antibodies against coronavirus (SARS-CoV-2) by using four chemiluminescence immunoassay systems. Methods Fifty patients diagnosed with SARS-CoV-2 infection and 130 controls without coronavirus infection from the General Hospital of Chongqing were enrolled in the current retrospective study. Four chemiluminescence immunoassay systems, including seven IgM/IgG antibody detection kits for SARS-CoV-2 (A_IgM, A_IgG, B_IgM, B_IgG, C_IgM, C_IgG and D_Ab), were employed to detect antibody concentrations. The chi-square test, the receiver operating characteristic (ROC) curve and Youden’s index were determined to verify the cut-off value of each detection system. Results The repeatability verification results of the A, B, C and D systems are all qualified. D_Ab performed best (92% sensitivity and 99.23% specificity), and B_IgM performed worse than the other systems. Except for the A_IgM and C_IgG systems, the optimal diagnostic thresholds and cut-off values of the other kits and their recommendations are inconsistent with each other. B_IgM had the worst AUC, and C_IgG had the best diagnostic accuracy. More importantly, the B_IgG system had the highest false-positive rate for testing patients with AIDS, tumours and pregnancies. The A_IgM system test showed the highest false-positive rates among elderly individuals over 90 years old. COVID-2019 IgM/IgG antibody test systems exhibit performance differences. Conclusions The Innodx Biotech Total Antibody serum diagnosis kit is the most reliable detection system for anti-SARS-CoV-2 antibodies, which can be used together with nucleic acid tests as an alternative method for SARS-CoV-2 detecting.

scholarly journals The Chi-Square test: a frequency data based statistical device

2015 ◽  
Vol 3 (3) ◽  
pp. 53-55 ◽  
Author(s):  
Ashok Kumar
Keyword(s):  
Significant Role ◽  
Statistical Significance ◽  
The Other ◽  
Frequency Data ◽  
Chi Square ◽  
Medical Researchers ◽  
Chi Square Test ◽  
Control And Eradication

“Cause Effect” relationships are very important and play a most vital and significant role in medical researchers to reveal efficacy of medication as preventive and curative measures towards control and eradication of various diseases and morbidity factors. The present paper, in this direction is an attempt to highlight the main applicability of - test ( chi- square test ) ; a most appropriate statistical device in testing statistical significance of the above mentioned relationships in studying impact of one on the other ; supplemented by a few citations thereof.

scholarly journals Level of Satisfaction in the Use of the Wraparound Hawley and Thermoplastic Maxillary Retainers

2019 ◽  
Vol 90 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Adenilson Silva Chagas ◽  
Karina Maria Salvatore Freitas ◽  
Rodrigo Hermont Cançado ◽  
Fabricio Pinelli Valarelli ◽  
Luiz Filiphe Gonçalves Canuto ◽  
...  
Keyword(s):  
The Other ◽  
Chi Square ◽  
Level Of Satisfaction ◽  
Intergroup Comparison ◽  
Significant Difference ◽  
Chi Square Test ◽  
Orthodontic Patients ◽  
Better Than

ABSTRACT Objective To compare the level of satisfaction in the use of wraparound Hawley and thermoplastic maxillary retainers. Materials and Methods The study sample included 70 orthodontic patients (24 males and 46 females), who were in the retention stage (mean age = 20.80 years). All patients wore the two types of maxillary retainer for 1 month each, along with a 3×3 fixed mandibular retainer. After the use of each retainer, the patients responded to a questionnaire evaluating the level of satisfaction with their use of the maxillary retainer. Intergroup comparison was performed by independent t tests. Chi-square test was used to evaluate preference for the type of retainer by gender. Results The thermoplastic retainer was better for swallowing and the wraparound Hawley appliance was better for hygiene and durability. The other factors evaluated (adaptation, speech, comfort, esthetics, satisfaction, and fitting) did not show significant differences between the retainers. There was also no significant difference in preference for the appliances. Conclusions Regarding the overall satisfaction and the preference, there was no difference between the wraparound Hawley and thermoplastic retainers. The wraparound Hawley appliance was better in hygiene and resistance than the thermoplastic retainer; and the thermoplastic appliance was better than the wraparound Hawley for swallowing fluids and saliva.

scholarly journals Comparing the Musculoskeletal Disorders of the Neck Between the Teachers of Physical Education and Other Majors in High Schools of Tehran City, Iran

2020 ◽  
Vol 11 (1) ◽  
pp. 43-50
Author(s):  
Elham Rahimipour Najafabadi ◽  
◽  
Reza Rajabi ◽  
Mohammad Hossein Alizade ◽  
Ali Mirabedi ◽  
...  
Keyword(s):  
High Schools ◽  
Physical Education ◽  
Musculoskeletal Disorders ◽  
Teaching Experience ◽  
The Other ◽  
Cluster Sampling ◽  
Regular Exercise ◽  
Chi Square ◽  
Chi Square Test ◽  
The Mean

Introduction: Musculoskeletal Disorders (MDs) largely contribute to occupational diseases in the workplace. Prevention from these disorders requires their evaluation in different occupations. This study aimed to compare the MDs of the neck between the teachers of Physical Education (PE) and those of the other majors in the high schools of Tehran City, Iran. Methods: The study sample included 180 teachers of mathematics, PE, and the religion and lifestyle in the high schools of Tehran (with the Mean±SD age of 42.11±6.65 years, and the Mean±SD weight of 72.28±12.98 kg). The participants were selected from 19 districts of the Tehran Departments of Education using multistage cluster sampling. The standard Nordic questionnaire was administered to investigate MDs among the teachers. The obtained data were analyzed with the Chi-square test to compare the MDs of the neck between the three groups of teachers. Results: A significant relationship was observed between the neck problems of the female (P=0.016) and male (P=0.017) PE teachers and the other teachers. Moreover, the neck problems were associated with the teaching experience (P=0.024) and teaching major (P=0.004). Conclusion: Based on the results, it seems that regular exercise can reduce the developing risk of MDs in the neck. Thus, this study recommends the performance of regular exercise and the correction of job-related postures to all teachers.

scholarly journals SPECIAL REQUIREMENTS FOR CORPORATE COMMUNICATIONS IN GEOGRAPHICALLY DEFINED MARKETS USING THE EXAMPLE OF THE SALE OF CONSTRUCTION FINANCING IN RURAL AREAS

2019 ◽  
Vol 2 (2) ◽  
pp. 185-193
Author(s):  
Christian Enz
Keyword(s):  
Rural Areas ◽  
Mortgage Lending ◽  
The Other ◽  
Corporate Communications ◽  
Chi Square ◽  
Savings Banks ◽  
Other Hand ◽  
New Business ◽  
Interest Policy ◽  
Chi Square Test

Private mortgage lending business is an important business segment for retail banks. There are two main reasons for this. Firstly, the comparatively low risk. On the one hand, because many years of experience in this segment enable optimal risk management. On the other hand, the financed properties also provide optimum security. Due to the small size of this business segment, private construction financing was unattractive for major banks for a long time. On the other hand, this division was a core business for regional banks and savings banks. However, as a result of the banking crisis in 2007 and 2008 and the ECB’s ongoing low-interest policy, the private mortgage lending sector is now attractive to all market participants. This is reflected in fiercer competition. The importance of customer communication has therefore also increased in the advertising for new business. Since financial and personnel resources are limited, corporate communications are faced with the challenge of addressing potential customers as efficiently as possible. Communication science has already developed a number of concepts for optimal, integrated communication. These are based on average consumers. Against the background of possible regional deviations in media usage and consumer behaviour, this work explains that banks and savings banks with a regionally defined business area should set different priorities within the communications mix than suprare­gional providers. To this end, a field study was conducted in rural areas of the Nuremberg metro­politan region and analysed using a chi-square test. The study revealed the continuing importance of branches and personal advice, despite increasing digitalisation. At the same time, the necessity of closely networking stationary sales and online offers in rural areas becomes clear.

scholarly journals WIND SPEED ANALYSIS AT IKEJA, NIGERIA USING THE CONVENTIONAL PROBABILITY DENSITY FUNCTIONS

2018 ◽  
Vol 24 (3) ◽  
Author(s):  
OLUSEYI OGUNSOLA ◽  
OGUNSOLA OSAGIEDE
Keyword(s):  
Likelihood Estimation ◽  
Information Criteria ◽  
Distribution Functions ◽  
Parameter Estimates ◽  
Energy Potential ◽  
Chi Square ◽  
Chi Square Test ◽  
Anderson Darling ◽  
Von Mises ◽  
Best Fit

<p>The wind energy potential at Ikeja (Lat. 6.35 °N; Long. 3.20 °E), Nigeria was statistically analyzed using three of the mostly utilized conventional Probability Distribution Functions (PDFs) in order to determine which of these distributions would give the best means of analysis for wind in this particular location. The best fit test for these PDFs were determined from Akaike Information Criteria, Bayesian Information Criteria, Kolmogorov-Smirnov test, Cramer-von Mises statistics, Anderson-Darling Statistic, Mean Square Error and Chi-Square Test using Maximum Likelihood Estimation and Method of Moments as parameter estimates. The Weibull distribution gave the best fit in this location.</p>

scholarly journals HUBUNGAN FREKUENSI PENIMBANGAN, PENGGUNAAN GARAM BERYODIUM, DAN PEMBERIAN VITAMIN A DENGAN KEJADIAN UNDERWEIGHT PADA BALITA DI PROVINSI JAWA TIMUR

2018 ◽  
Vol 12 (1) ◽  
pp. 40
Author(s):  
Nafijah Muliah ◽  
Agus Sri Wardoyo ◽  
Trias Mahmudiono
Keyword(s):  
Vitamin A ◽  
Nutrient Intake ◽  
Secondary Data ◽  
Iodized Salt ◽  
The Other ◽  
Chi Square ◽  
Vitamin A Supplementation ◽  
Chi Square Test ◽  
Households With Children ◽  
The Relationship

The are many causes of nutritional problems, including lack of food intake, illness, caring pattern and many other causes, one of the problems that often happen is the children had not weighed regularly. Iodine is one of the nutrients associated with the growth of children. On the other hand, children who are suffering from malnutrition usually also hasVitamin A defi ciency as a result of their lack of nutrient intake. The purpose of this study was to analyze the relationship between the frequency of weighting, the use of iodized salt, and Vitamin A supplementation with underweight among children under fi ve in East Java Province. This study was secondary data analysis from Monitoring of Nutritional Status (MNS) in East Java, 2016. The sample of this study were 10.440 households with children under fi ve. 18.5% children under fi ve in East Java were underweight, 2% overweight, and 79.5% were normal. Distribution of frequency were performed as univariate statistical analysis and the relationship between variables were analyzed by chi-square test. The odd ratio were analyze by logistic regression. There was signifi cant correlation between blue-colored vitamin A supplementation (p < 0.001;OR = 0.638;95%CI:0.580-0.78w2) with underweight. However, there was no correlationbetween weighing frequency (p = 0,729) and the use of iodized salt (p = 0,620) with underweight. The conclusion of this study highlight that there was correlation between Vitamin A supplementation with underweight in East Java.

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