Mathematical Study: The consumer price index in the expenditure sub group using factor analysis

Inflation is very important monetary event and is often found in almost all countries in the world. In this research, it will be known what factors influence the inflation rate of Central Java in 2019. The method used is the Factor Analysis method with the Principal Component Analysis technique. Factor Analysis is one of the interdependent multivariate analysis techniques by reducing data to create a new variable (called a factor) and conducting an independent variable analysis into variables that correlate with other variables in the factor. The results of this factor analysis research, obtained two factors formed from 11 variables (expenditure sub-groups) with the largest contributor to inflation in Central Java in 2019. Factor 1 consists of Preserved Fish variable ( X 1 ), vegetables variable ( X 2 ), Fruits variable ( X 3 ), Seasonings variabel ( X 4 ), and Non-Alcoholic Drinks variabel ( X 5 ). Furthermore, this factor is named foods and beverages factor. Meanwhile, factor 2 consisted of Tobacco and Alcoholic Beverage variable ( X 6 ), Household Management variable ( X 7 ), Education Services variable ( X 8 ), Educational Equipment variable ( X 9 ), Courses/Training variable ( X 10 ), and Support Facilities for Transport variable ( X 11 ), was then given the name of the Tobacco, Services and Facilities factor.