An aerobic exercise instructor remembers the data given in the following table, which shows the recommended maximum exercise heart rates for individuals of the given ages. (A graphing calculator is recommended.) Age (x years) Maximum heart rate (y beats per minute) (a) Find the linear correlation coefficient for the data. (Round your answer to two decimal places.) 20 40 60 174 158 142 (b) What is the significance of the value found in part (a)? The linear correlation coefficient should always be positive. The graph of the regression points passes through none of the data points. The graph of the regression points passes through all three data points. The slope of the regression is about half of what the expected value is. One of the data points is the y-intercept. (c) Find the equation of the least-squares regression line. (Round your answers to two decimal places.)