Before you can interpret the numerical value of r, you need to determine if it was appropriate to calculate r to begin with. The Pearson correlation coefficient, r, describes the strength and direction of a linear relationship between two variables. The first step in exploring a linear relationship is to generate the scatterplot, which you learned about in the previous section.
New Smog Check Test Smog Check Program's Updated Test Technology Californians getting Smog Checks today may notice that the traditional tailpipe test used for many years has been replaced by a quicker, computer-based test for gasoline-powered cars model-year 2000 and newer, and for most diesel vehicles that are model-year 1998 and newer.
What are the vehicle inspection requirements in CA? Clean air is a priority in the state of California, and vehicle emissions testing is required for most vehicles at every other registration renewal period. Regular vehicle maintenance, prior to emissions testing, helps spot and repair potential problems to avoid delays in registration due to a failed smog test.