Inflation is a problem which haunts the economy of each country. Its development is which continually increasing make a drag on economic growth to a better direction. Inflation tends to occur in developing countries like Indonesia which is an agricultural country. To overcome the instability of inflation, one way to do is to predict the time series data. Methods Autoregressive Integrated Moving Average (ARIMA) has the ability to capture the necessary information about the wood as well as able to cope with the instability of inflation of inflation. This is because ARIMA is a method of forecasting time series are suited to predict the number of variables in a fast, simple, inexpensive, accurate, and only requires the data variables to be predicted. Inflasi merupakan suatu masalah yang menghantui perekonomian setiap negara. Perkembangannya yang terus-menerus mengalami peningkatan menjadi hambatan pada pertumbuhan ekonomi ke arah yang lebih baik. Perubahan laju inflasi cenderung terjadi pada negara-negara berkembang seperti halnya Indonesia yang merupakan negara agraris. Untuk menanggulangi terjadinya ketidakstabilan laju inflasi, salah satu cara yang dapat dilakukan adalah dengan meramalkan data time series. Metode Autoregressive Integrated Moving Average (ARIMA) memiliki kemampuan untuk menangkap informasi-informasi yang diperlukan mengenai laju inflasi serta mampu menanggulangi ketidakstabilan dari laju inflasi. Hal ini dikarenakan ARIMA merupakan suatu metode peramalan time series yang cocok digunakan untuk meramal sejumlah variabel secara cepat, sederhana, murah, dan akurat serta hanya membutuhkan data variabel yang akan diramal.

Students in normal circumstances carry out direct learning through Face-to-Face Tutorials (TTM) but in the pandemic era, they adapt to the Webinar Tutorial (Tuweb) using the Microsoft team. The research objective was to see the analysis of the concept of andragogy in Tuweb learning. Tuweb is synchronous learning. The method used in this research is explanatory sequential mixed methods (explanatory sequential mixed methods). The results found that adult learning styles (andragogy) in the aspect of self-concept (emotionally stable students, they are adults who are mature, cognitive, and developmentally mature), the concept of experience (requirements to become a student in the teaching field of at least one year ) teaching, as evidenced by a decree (SK) from the relevant agency), the concept of learning readiness, time perspective or learning orientation. The mean score of students' andragogical ability was 84.8 or in the high category.

Covid-19 has become a global epidemic and has spread to many countries in the world, including Indonesia. The COVID-19 pandemic is one source of uncertainty that causes financial data to fluctuate and cause data to be volatile. This outbreak had an impact on financial data, not only on the Rupiah exchange rate but also on the Jakarta Composite Index (JCI). The uncertainty of the JCI makes it difficult for investors, data managers, and business people to predict data for the future. JCI is one indicator of the capital market (stock exchange). The uncertainty of the JCI data causes the need for predictions, so that investors, data managers, and business people can make the right decisions so that they can reduce risk and optimize profits when investing. One of the factors causing the JCI's decline was sentiment caused by investor panic over the rapid spread of COVID-19 in various cities in Indonesia. This research uses Backpropagation Neural Network (BPNN) in making predictions and continues with optimization of BPNN using ensemble techniques. Historical data from the JCI used were obtained from yahoo.finance. The ensemble technique used consists of two approaches, namely combining different architectures and initial weights with the same data and combining different architectures and weights. The results of network performance using ensemble technique optimization show good performance and can outperform the individual network performance of BPNN. Keywords: prediction, JCI, Optimization, BPNN, volatile