Mikailalsys Journal of Mathematics and Statistics

Application of Queue Theory in Cafe Services with Erlang Distribution

Bagus D. Ramadhani — 2024-07-21

As urban lifestyles evolve, culinary businesses, particularly cafes, have experienced rapid growth. This surge in popularity has led to an increase in customers and, consequently, longer queues. These extended wait times can frustrate customers and pose challenges to cafe management. To address this issue, we conducted a comprehensive eval_uation and optimization of the service system at a Samarinda cafe using the Erlang distribution queuing system. Primary data was meticulously collected over six days, amounting to a total of 12 hours of observation. Kolmogorov-Smirnov distribution fitting tests were employed, revealing that customer service times adhered to an exponential distribution. The average customer arrival rate was determined to be 0.351 per minute, while the average service time was calculated at 5.546 minutes per customer. Our analysis confirmed that the system operates in a steady state with a utility value of 0.06, indicating sufficient service capacity to handle the current customer load. Therefore, the study concludes that the cafe's service system is currently optimal.

Statistical Estimation and Inference of Board Composition on Financial Performance of Oil and Gas Companies in Nigeria

Danjuma Idi — 2024-07-31

This study examines the relationship between board characteristics and financial performance of listed oil and gas firms in Nigeria, highlighting the gap in existing literature on the topic. The purpose of this study is to investigate the impact of board independence, board size, and gender diversity on financial performance. A sample of three listed oil and gas firms on the Nigerian Exchange Group (NGX) was selected, and secondary data from annual financial statements for 2010-2021 were analyzed using panel regression and correlation analysis. The findings reveal that female board members have a positive and significant impact on financial performance, while board independence and board size have a positive but insignificant impact. The study concludes that gender diversity on boards is a key factor in driving financial success, and recommends increasing the number of female board members to improve financial performance. The results contribute to the understanding of the relationship between board characteristics and financial performance in the Nigerian oil and gas industry.

F-Test and Analysis of Variance (ANOVA) in Economics

Nand Kishor Kumar — 2024-08-23

ANOVA remains a cornerstone of empirical economic research, providing economists with a robust framework to analyze differences between groups, eval_uate policy interventions, and draw meaningful conclusions from data. Its versatility and applicability across diverse economic contexts underscore its significance in advancing economic theory and informing evidence-based policymaking. As data availability and computational capabilities continue to expand, ANOVA's role in economic analysis is expected to evolve, supporting increasingly sophisticated studies of economic phenomena and policy impacts. In economics, particularly in empirical research and data analysis, the F-test and Analysis of Variance (ANOVA) are fundamental statistical tools used to test hypotheses regarding the equality of means across two or more groups.

Analysis the Effect of Inflation, Gold Prices in Dollars, Rupiah Exchange to Bank Indonesia Monthly Rates After the COVID 19

Dimas Nugroho Dwi Seputro — 2024-09-04

The Covid-19 pandemic has caused economic turmoil to become uncertain, affecting all aspects of Indonesian society's lives. This research aims to determine the relationship between the inflation rate, the transaction price of the last issuer of gold and the rupiah exchange rate that occurred in the period after the Covid-19 pandemic on the monthly interest rate of Bank Indonesia, both together and each variable on the monthly interest rate of Bank Indonesia. This research details the research steps starting from classical assumption test analysis, multiple linear regression, coefficient of determination to hypothesis testing. The research results show that from the inflation rate, the price of gold in dollars together has a significant influence on the dependent variable, namely the Bank Indonesia monthly interest rate. Inflation and gold prices in dollars partially have a significant influence on Bank Indonesia's monthly interest rate, while the rupiah exchange rate variable partially does not have a significant influence on Bank Indonesia's monthly interest rate. Inflation is the most dominant variable in Bank Indonesia's monthly interest rate after the Covid-19 pandemic.

Comparison of Value at Risk (VaR) in Risk Analysis: Historical, Variance Covariance and Monte Carlo Methods

Meirinda Fauziyah — 2024-09-04

Value at Risk (VaR) is a method used to measure financial risk in a company. VaR calculations are often used to calculate the level of loss from shares in a company, such as bank shares. The aim of this research is to determine the level of losses in Bank Central Asia shares using the historical method, the Variance-covariance method, and the Monte Carlo method. the results showed that with an initial investment of $50 and using the Historical method at a significant level of 95%, the VaR value was obtained at $16.42 or IDR. 267.301 and at the 90% significant level, the VaR value was obtained at $12.41 or IDR. 202.022. Based on the Variance-covariance method with an initial investment of 50$ at the 95% significant level, the VaR value is obtained at $16.42 or IDR. 267,301 and at the 90% significant level, the VaR value is obtained at $12.79 or IDR. 208.208. Meanwhile, based on the Monte Carlo method with an initial investment of $50, at a significant level of 95%, the VaR value is obtained at $16.46 or IDR. 267,952 and at the 90% significance level, the VaR value is obtained at $12.84 or IDR. 209.022. Based on the three methods used, it was concluded that the Monte Carlo method gave greater results compared to the other two methods.

Novel Extended Weibull Regression Model for Investigating the Survival Times of Breast Cancer Patients

Ahmed Abdulkadir — 2024-09-17

The new five-parameter alpha power generalized odd generalized exponentiated Weibull distribution is introduced, and some of its structural properties are derived. Its parameters are estimated by maximum likelihood, and a simulation study examines the accuracy of the estimates. A regression model is constructed based on the logarithm of the proposed distribution to investigate the survival times of breast cancer patients in Bauchi State, Nigeria. The applicability and flexibility of the novel model is proven by means of cancer dataset.