Logistic regression is a statistical technique to find the association between the categorical dependent (response) variable and one or more categorical or continuous independent (explanatory) variable. We can define the regression model as, G(probability of event)=β0+β1×1+β2×2+…+βkxk We determine G using link function as following, Y={1 ; β0+β1×1+ϵ>0 {0 ; else There are three types of […]
Data levels in statistics indicates the measurement levels in statistics. In statistics, the statistical data whether qualitative or quantitative, are generated or obtain through some measurement or some observational process. Measurement is essentially the task of assigning numbers to observations according to certain rules. The way in which the numbers are assigned to observations determines […]
Business forecasting is the process of making prediction of the future based on past and present data. In many cases a reliable forecast can be worth a lot of money, such as consistently and correctly guessing the behavior of the stock market for enough in advance to act upon such a guess. Business forecasting In […]
Inference comes from a word ‘infer’ which means that to draw a conclusion about a phenomenon on the basis of some information at hand. To make inference about a phenomenon through some statistical procedure is called statistical inference. According to wikipedia, “Inferences are steps in reasoning, moving from premises to logical consequences”. Types of statistical inference Statistical inference may be […]
Time series analysis is an impotant forcasting procedure to find the trend of time series data. It is an important statistical procedure to analyze the time trend data and make interpretation from the analysis result. According to wikipedia, “In mathematics, a time series is a series of data points indexed (or listed or graphed) in time order.” Time […]
The relationship between two or more random variables are generally defined as the correlation. It is the major part of bivariate analysis. When variables are found to be related, we often want to know how close the relationship is. The study of the relationship is known as correlation analysis. The primary objective of correlation is […]
Skewness and kurtosis are two important measure in statistics. Skewness refers the lack of symetry and kurtosis refers the peakedness of a distribution. Skewness Literally, skewness means the ‘lack of symmetry’. We study skewness to have an idea about the shape of the curve which we can draw with the help of the given […]
Quadrat sampling is a classic tool for the study of ecology, especially biodiversity. It is an important method by which organisms in a certain proportion (sample) of the habitat are counted directly. It is used to estimate population abundance (number), density, frequency and distributions. The quadrat method has been widely used in plant studies. A […]
The wilcoxon signed rank test determine whether the median of the sample is equal to some specified value. The Wilcoxon signed rank test utilizes both the sign of the difference as well as the magnitude of the differences, hence it provides more information than the sign test, it is often more powerful non-parametric test. Assumptions […]
In many situation, we are interested to whether the data collected for statistical analysis is random or not. In most all statistical inference we assume that the data is in a random sample. If the randomness of a sample is suspected, we test it’s randomness before, going to statistical analysis. In detail, There are many […]
