When
to use regression, correlation and covarianceImagine that you'd like
to know what kind of behaviors lead to winning baseball teams, or what kind of
behaviors or treatments lead to optimal results for patients. In baseball, you
would want to know if walks, hits, errors, etc. lead to winning teams. In healthcare,
you might want to know if walking 30 minutes a day leads to better cholesterol
levels. While statistical analysis cannot prove that one thing causes another,
it can determine if there is a relationship between the variables which gives
a direction to the analysis. Correlation
and Covariance: To understand and explore the
relationships between two or more sets of numbers, Excel provides means to analyze
the variance (i.e., co-variance) and linear relationships (i.e., co-relation)
between two or more sets of numbers. In the healthcare example, correlation and
covariance could identify relationships between minutes walking and cholesterol
levels (HDL, LDL, VLDL).
Regression:Excel also offers
the ability to handle regression analysis on two or more sets of
data. Regression analysis determines how one or more independent
variables affect a single dependent variable. In the baseball
example, how do walks, hits, and errors (independent variables)
affect wins (dependent variable)?
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