One of your first steps when looking at a dataset should be to look at a picture. We saw this previously in chapter 3 with looking at histograms to determine if a dataset appeared to look symmetrical or skewed. This was important to help us determine the appropriate average (mean or median) and spread value (standard deviation or IQR) to use with that dataset. When looking at linear regression, we should start with a picture (scatter diagram) before calculating the linear correlation coefficient or least-squares regression model. Why is this important?