If we know the value of one variable in an individual and wish to know the value of another variable, we calculate -
Coefficient of correlation
Coefficient of regression
SE of mean
Geometric mean
REGRESSION:

Is change in measurements of a variable
Provides structure of relationship between 2 quantitative variables
Regression Coefficient (b): Measure of change of one dependent variable (y) with change in independent variable (x) or variables (x1, x2, x3……)

Equations of regression,
y = a + b (x)
y = a + b (x1) + c (x2) + d (x3),
where y is a dependent variable and x, x1, x2, x3 are independent variables; a is a constant and b, c, d are regression coefficients

Types of regressions:

– Simple linear regression: Only one dependent variable and one independent variable
– Multiple linear regression: Only one dependent variable and more than one independent variable
– Simple curvilinear regression: Only one dependent variable and one independent variable, with some power of independent variable
– Multiple curvilinear regression: Only one dependent variable and more than one independent variables, with some power of independent variables).

Types of regression equations: