Biostatistics: What is Dichotomous variable?

A dichotomous variable, also known as a binary or categorical variable, is a type of variable that can take on one of only two possible values. These values are typically coded as 0 and 1, where each value represents one of two exclusive categories or states. Dichotomous variables are used in statistical analysis and research to represent outcomes, characteristics, or attributes that are inherently binary in nature. Examples of dichotomous variables include: Gender: Coded as 0 for female and 1 for male (or vice versa). Presence or absence of a condition: Such as disease status, with 0 indicating absence and 1 indicating presence. Response to a question: Such as “yes“ or “no“ answers, coded as 1 for yes and 0 for no. Dichotomous variables are particularly useful in research and biostatistics for simplifying complex data into a form that is easier to analyze and interpret. They play a crucial role in logistic regression, chi-square tests of association, and other statistical methods designed to analyze relationships between variables or compare groups based on binary outcomes. Problems: Which of the following is a dichotomous variable? А) Sex * В) Pain yes/ Pain no * С) NYHA I-IV D) alive / dead * E) Grade of Breast Cancer In normal distribution, what percentage of the sample is found within 2 standard deviation of the mean? A) 68% B) 95% * C) 99% D) 100% E) 72%