The ordered pairs below give the winning times (in seconds) of a 100-meter freestyle swim race at a regularly-held competition from 1984 through 2012. (1984, 55.12) (2000, 53.03)
(1988, 54.13) (2004, 53.04)
(1992, 53.84) (2008, 52.32)
(1996, 53.70) (2012, 52.20)
(a) Sketch a scatter plot of the data. Let y represent the winning time (in seconds) and let
t = 84 represent 1984.

(b) Sketch the line that you think best approximates the data and find an equation of the line. (Round the slope and y-intercept to one decimal place.)
y =

(c) Use the regression feature of a graphing utility to find the equation of the least squares regression line that fits the data. (Round the slope and y-intercept to two decimal places.)
y =