Moving on to chapter three in statistic textbook, we learned about the relationship of scatterplots, correlation, and the least-squares regression. The scatterplot is the most common and effective way of showing the relationship between the two quantitative variables. On the scatterplot display one variable of the horizontal axis (the X-axis), and another variable appears on the vertical axis (the Y-axis). In the horizontal axis, we usually plot the explanatory variable (independent variable) and response variable (dependent variable) on the vertical axis. Correlation is a type of statistical measure that includes two or more variable shift together. Correlation is also a strategy that shows how strong the variables are related. Regression line or line of best fit that are being plotted in the scatter graph is shown to display a relationship that can possibly be used in order to predict the values of one variable as a guide to finding another unknown variable.