What is the impact of more than one independent variable on a dependent variable. This is explained by Multiple Regression Model.
y = b0 + b1x1 + b2x2 + e
where b0 = constant intercept on the y-axis
b1 , b2 – slope coefficients of the independent variables.
x1, x2 – independent variables
e = Error term which is difference between calculated value of y – actual value of y
The above equation can be put into use only if the coefficients are significant. This is confirmed using hypothesis test.
Hypothesis testing can be one tailed or 2 tailed.