Hypothesis Testing Hypothesis tests, also called significance tests, are ubiquitous in the traditional statistical analysis of published research. Their purpose is to help you learn whether random chance might be responsible for an observed effect. KEY TERMS Null hypothesis The hypothesis that chance is to blame. Alternative hypothesis The counterpoint Read more…
This is part 2 of Introduction to Dimensionality Reduction. In this blog post, we would several different mathematical prerequisites that one must know before trying to understand machine learning. Mean Vector The sample mean is a vector each of whose elements is the sample mean of one of the random Read more…
In statistics, a confidence interval (CI) is a type of interval estimate which we compute using the statistics of the observed data. The interval has an associated confidence level that, loosely speaking, quantifies the level of confidence that the value of the parameter lies in the interval. For eg, if Read more…
Suppose you have taken the data for heights and weights of students in class and you want to figure out the correlation between heights and weights of students. The relation between these two parameters is defined mathematically by one of the 3 ways 1) Covariance 2) Pearson Correlation Coefficient 3) Read more…
Types of Distributions Bernoulli and Binomial distribution A Bernoulli random variable has two possible outcomes: 0 or 1. A binomial distribution is the sum of independent and identically distributed Bernoulli random variables. So, for example, say I have a coin, and, when tossed, the probability it lands heads is p. Read more…
Populations and Samples The main difference between a population and a sample has to do with how observations are assigned to the data set Population Includes all of the elements from a set of data. Sample Consists of one or more observations from the population. Probability Density function(PDF) The PDF, Read more…
Random Variables The term random variable is not very descriptive. A better term is measurement function.Consider tossing a fair six-sided die. There are only six outcomes possible, Ω = {1, 2, 3, 4, 5, 6} As we know, if the die is fair, then the probability of each outcome is Read more…
Measures of central tendency To represent a quick summary of data we use several mathematical methods. These methods usually try to determine where the center of the dataset lie. There are three mathematical measures and they all have their own unique features: Mean Median Mode Mean is simply the average of Read more…
Using the right Graphs are very important for representing the right type of data.We can say Data in statistics is of the following types For reading the details on all the different data types read here. https://towardsdatascience.com/data-types-in-statistics-347e152e8bee For representing categorical data, we use bar charts, pie charts and Read more…